Well, don't keep Selanne or Brodeur because of age. Selanne was lucky to produce what he did last year. I would cross off Elias as well, as the 36 year old is unlikely to replicate last years stats.
Iginla is also getting up in age and while he's ultra talented, he is slowing down, and that poor Calgary team doesn't help. So it's really down to Eriksson, Moulson and Koivu.
Eriksson is a solid, consistent performer and should be kept. Moulson and Koivu are quite even but Koivu is the better playmaker and Moulson will pot the goals playing with John Taveras. I would keep Moulson, because goal scorers are harder to come by, he will put up a lot more shots than Koivu, and has shown to be more durable.
Koivu also is ranked lower so he could be had early in a draft, too.