Honestly, it doesn't look like they've done anything with the engine at all, just looks like Crysis 1 with different environments. Which isn't all that bad, Crysis was way ahead of its time, but some games have caught up/exceeded it now.
I do however like the look of the MP, although it looks like they just stole elements of every other MP game out there to come to that. Looks like they stole some MW2(knife, some gameplay elements) stole some from AVP(sneak up behind for melee insta-kills, thermal vision) and some Bad Company 2(semi-destructible environments, some gameplay elements) Use what works I guess, I'd rather have good MP stolen from everyone else than some bad crap they cooked up. I prefered the super punch over the knife though, hope its still there.