Well, I "beat" the second area, haven't managed to "beat" the first area.
Having an AI buddy is kind of annoying/distracting while I'm fighting off zombies. I'd rather play solo the first time to beat it and then co-op after. (i did try co-op a couple times though, it was good).
I like the girl, nice accent.
Still has that Resident Evil feel to it, not super fast paced like other shooters.
Graphics are gorgeous, not a jaggie in sight (uh oh PS3). The only bad are some ugly textures from indoor objects and very minor screen tearing towards the top which isn't too distracting.
EDIT: I guess I'll give my full impression.
Sound is ok, sound effects are weak though.
The guns don't feel like that have much weight, or power. The rifle, machine gun, even the shotgun... they all felt weak.
So far, not as amazing as when you first played RE4.
I'll give the demo a 6.5/10. Still good. I think online co-op will be what makes the game.