I saw it last night and both me and my mate loved it, not overall as good as the excellent Iron Man but hulk had better actions scenes and pacing. The acting and writing for both is brilliant though.
I'm not a massive Hulk fan so I didn't know who the excitable scientist in blue was untill I read this thread but it was clear from what happened that he will be an important character in the next film.
Ed Norton was really good as Bruce Banner, far more convinincg then I was expecting from him and Liv Tyler was good too. Tim Roth was playing a right savage from the get go.
As far as the numerous cameo's go, I caught Lou Ferringo but missed Bill Bixby. Tony Stark's scene did seem a bit shoved in there due to the reshuffling that they must have done. I wonder, did so many people walk out of Iron Man without seeing Fury that they decided not to do that again.