IMO, although the Heatley/Thornton/Marleau line is playing great lately, SJ will have to spread out their offense through the top 6 in the near future. Playing against teams with good top 2 Shutdown as is the recent games vs Calgary and St. Louis. It's too easy to defend if you are a one-line team.
If Marleau playing with Pavelski and Clowe can produce some points, while Seto can only produce when playing with Jumbo and Heater, then a smart coach will move Marleau down. Not because he isn't good enough, but BECAUSE he's good enough.
Same case with last year's Canucks, Kesler and Burrows play great together, so great that it was worth spreading them across the lines, and it worked out near the latter part of last season.
Even the coach himself said, he is just easing Seto in, he WILL be back on the top-line down the stretch.
So, yes you should bet on San Jose, rather than the Islanders.