Found these. They aren't the best quality but it gives you an idea of how the game looks graphically. (This isn't my twitpic btw)

http://twitpic.com/photos/Vfixxxerv

Why must you make me turn my head to see the pictures.... why...

Nice teaser pics.. no sarcasm..

The graphics dont looks radically different, its likely the same engine as the first game.

It will be, but tweaked and enhanced.  They said they are making it look a little more gritty as well.  This is fine with me since I loved the graphics engine on the first one.

Same, I really hope the city isnt a exact copy of the first game. It's sounding more and more like they just took the first game and reskinned it with a multiplayer focus. I hope theres actually compelling new content

Well, from a story perspective, the city wouldn't change.

As for adding new features there are tons of new things:

4 player co-op

16 player multiplayer

New weapons

New vehicles(ones with gun turrets)

New enemies(some as powerful as the agents)

More varied mission types

Unlockable rewards

So just from that list of confirmed features, it is as much a full blown sequel as any sequel.

True, but I was expecting a proper sequel with, if not a brand new location (the last game did end with "pacific city is only the beginning", a redesigned pacific city. The most fun I had with the first game was the platforming, which will be identical in the sequel

I came buckets reading that 16 player multipalyer is gonna be insane.

I wasn't excited for this game before GI. Then after I read the article I am now genuinly excited for this now

i was worried when i heard zombies.... now .... awesome