Far Cry 2 will pale in comparison to Crysis. Crysis is the proper follow up to Far Cry, even if it's not technically a sequel.
You know, I wonder if Crytek were forward thinking in the naming of their company and game, or whether it was just lucky? I mean if the company wasn't called Crytek, they probably wouldn't have been able to call their new game Crysis as it would be too similar to Far Cry, and the only reason to call it that would be to make people associate it with Far Cry. But because they are called Crytek, they have a legitimate reason for calling it Crysis.