I think that Cuomo is trying to show "Party unity" and support Paterson. Since Paterson will go down in flames, (Even against Lazio, lol) he can position himself perfectly for the office in 2014.
Why wait four years if you can have the office today? Besides, if he waits four years, he might never be President. If he runs in 2010, he could position himself perfectly for 2016 (assuming Hillary doesn't run), since he'll have an impressive resume and still be pretty young. Then again, maybe he doesn't want to be President (just like his dad didn't run for the office in 1988 and 1992 when the nomination was his for the taking).
His dad wanted to be President. He didn't want to run against Bush, who's popularity was at stratospheric levels. Clinton took a risk, and it payed off for him. Cuomo made the biggest political error of his life.
Cuomo is trying to appeal, I think, to party unity. Of course it is his for the raking, but he'd be an ass in challenging a member of his own party for the office. he probably thinks that it will make him seem noble if he doesn't run. Then again, maybe he will run, and win. You can't be sure.
