Here are some assets found by more savvy folks than I. Looks like a much better lineup (to me personally anyway) than the first game. Not sure exactly what role GLaDOS is playing here, maybe you play as her?
@chaser324: I thought the same thing for a bit until I found the direct links,
Oh wow, never thought I'd see Brock from Venture Bros. appearing in a game like this, that does make me very happy, and the Portal room looks cool. I don't have much of a love for the other characters apart from GLaDOS though, and I have my problems with Claptrap in particular. The first Poker Night was also kinda cool, but when it came down to it not an amazing poker game. I think I might pass on this one. What a weird line-up of characters they have.