Why should Crysis 2 be like the original? Yes, it should resemble it in some ways, but you really can't expect Crytek to make the same game twice. If you want Crysis, go play Crysis. The sequel will be different. That's how sequels are. In this case, the formula is not staying exactly the same. And to me, it feels fairly unique.
Everyone's comparing it to Call of Duty simply because it's another shooter. Well yes, the two games will indeed be similar BECAUSE THEY'RE IN THE SAME GENRE. In both games, you shoot, jump, and run around the map. In Crysis 2, you also get to turn invisible, crash through stuff, etc. I plead with the community here, please don't compare the two games just because you can...
Crysis 2 will be different than its predecessor. But I've only been attracted to the game series BECAUSE of this sequel. The hardcoe Crysis fans may not be entirely satisfied with the new incarnation of their much-loved game, but if Crytek wanted to release the exact same thing again, it would svck.