There is a very good possibility that the 480 wont have the full 512 shaders, been rumors flying around forever and i read in a recent article, that when nvidia was flat out asked they said they wont disclose that.
If it has less than the full 512 we would all be fools to buy one, in a few months 6 tops they will have the newer better full 512 ones out.
And after seeing a cherry picked benchmark that shows the 480 is equal to the 5870 for all intents and purposes as far as gaming goes, i am starting to lose faith.
Tesselation means squat diddly for games, maybe in a few years it will be heavily used but its a moot point right now. And all i ever hear nvidia talk about is, bloody tesselation, must be the only good thing about the card ;(