It's not as amazing as the first part but still it's a great shooter
First the graphics: I think that Crysis 1 has overall better graphics than Crysis 2, but in some elements like the lights/shadow effects in the second one are much better. In general the game looks great but not as great as one would expect having in mind that it should overcome the first one graphically.
Crysis 2 as a game: The game lacks the liberty the first one offer, although it gives you some different ways of playing and you actually choose the style you want to play. If you're experienced in shooters the best way to play the game is on the highest difficulty level to find some real challenge, since the AI is not really brilliant (compared to the Crysis 1 AI). I think that the way the story is told in Crysis 2 is really good and makes you keep playing the game for a while, and there's also a good amount of action making the campaign really great.
Personally I think that after Crysis 1, Crysis 2 is one of the best shooters from this generation (unlike the COD crap) and it's probably going to be the best of this year!