I only ask because Game Informer dropped a huge bombshell with info and pics on Resistance 2.
60 player multi-player
8 player story co-op on a separate compaign from the single player one
Partially randomized geometry
Online matching
AI improvement with enemies becoming more aware of your presence, the closer you get to them.
There's more stuff, but that's just some off the top of my head.
Here's a comparison photo from Resistance 2 and Resistance 1 - http://www.enregistrersous.com/image...0111220040.jpg