US tennis player Serena Williams (C) is pictured during a book signing at Harrods department store in London, on November 2, 2009. Williams was promoting her book entitled "Serena Williams, My Life, Queen of the Court". AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

US tennis player Serena Williams (L) poses for a picture with a fan during a book signing at Harrods department store in London, on November 2, 2009. Williams was promoting her book entitled "Serena Williams, My Life, Queen of the Court". AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

US tennis player Serena Williams is pictured during a book signing at Harrods department store in London, on November 2, 2009. Williams was promoting her book entitled "Serena Williams, My Life, Queen of the Court". AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

US tennis player Serena Williams is pictured during a book signing at Harrods department store in London, on November 2, 2009. Williams was promoting her book entitled "Serena Williams, My Life, Queen of the Court". AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

US tennis player Serena Williams is pictured during a book signing at Harrods department store in London, on November 2, 2009. Williams was promoting her book entitled "Serena Williams, My Life, Queen of the Court". AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

US tennis player Serena Williams is pictured during a book signing at Harrods department store in London, on November 2, 2009. Williams was promoting her book entitled "Serena Williams, My Life, Queen of the Court". AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

US tennis player Serena Williams is pictured during a book signing at Harrods department store in London, on November 2, 2009. Williams was promoting her book entitled "Serena Williams, My Life, Queen of the Court". AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

US tennis player Serena Williams smiles during a book signing at Harrods department store in London, on November 2, 2009. Williams was promoting her book entitled "Serena Williams, My Life, Queen of the Court". AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

US tennis player Serena Williams smiles during a book signing at Harrods department store in London, on November 2, 2009. Williams was promoting her book, "Serena Williams, My Life, Queen of the Court". AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

US tennis player Serena Williams smiles during a book signing at Harrods department store in London, on November 2, 2009. Williams was promoting her book, "Serena Williams, My Life, Queen of the Court". AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

Serena Williams of the US returns to her sister Venus during their WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US returns to her sister Venus during their WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US returns to her sister Venus during their WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US poses with her trophy and her prize after beating her sister Venus in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US poses with her trophy after beating her sister Venus in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US (R) and her sister Venus (L) pose with the daughter of the Qatari Emir, Sheikha Hind bint Hamad al-Thani (C), after receiving their trophies following their WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US (R) receives the winner's trophy from the daughter of the Qatari Emir, Sheikha Hind bint Hamad al-Thani (L), after beating her sister Venus in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US (R) receives the winner's trophy from the daughter of the Qatari Emir, Sheikha Hind bint Hamad al-Thani (L), after beating her sister Venus in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US poses with her trophy after beating her sister Venus in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US (C-R) poses with her trophy after beating her sister Venus (L) in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US (R) poses with her trophy after beating her sister Venus (L) in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US (R) poses with her trophy after beating her sister Venus (L) in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US (R) poses with her trophy after beating her sister Venus (L) in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US poses with her trophy after beating her sister Venus in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US poses with her trophy after beating her sister Venus in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US poses with her trophy after beating her sister Venus in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US poses with her trophy after beating her sister Venus in the WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena Williams won her second career WTA Championships title with a commanding 6-2, 7-6 (7/4) victory over sister Venus, a triumph which earned her a cool 1.55 million dollars. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Qatari men attend the match between Serena Williams of the US and her sister Venus during their WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Serena won the WTA Championships title beating sister Venus, the defending champion, 6-2, 7-6 (7/4) in the final. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

A general picture shows the match between Serena Williams of the US (L) and her sister Venus (R) during their WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Defending champion Venus Williams and sister Serena are clashing for the 23rd time in their careers in the final of the 4.55 million dollar WTA Championships. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

Serena Williams of the US serves to her sister Venus during their WTA Championships final tennis match at the Khalifa International Tennis and Squash Complex in Doha on November 1, 2009. Defending champion Venus Williams and sister Serena are clashing for the 23rd time in their careers in the final of the 4.55 million dollar WTA Championships. AFP PHOTO/KARIM JAAFAR (Photo credit should read KARIM JAAFAR/AFP/Getty Images)