Ok, so I went and saw this last night, and I think it was pretty cool to be honest.
I'll make some observations, but I don't wanna fill it full of spoilers, so they will be pretty broad.
Bad stuff:
Storyline - Yes the storyline in this one was pretty superficial, there was far too much "tell, don't show" for my personal taste, but considering the length of the movie I am not too sure IF more storyline would have actually helped or detracted from the movie. The other thing hampering the story (which was pretty unavoidable) was the use of so many essentially "lead characters" (Iron Man, Cap and Thor) in the one pic. Again however it was pretty unavoidable. One thing to bear in mind though, the movie is about the "birth" of the Avengers *as a team*, NOT the background stories of the major characters which are handled in thier own movies, and taking that into consideration it DID fulful that role (and YES bluce, there is some avenging going on, in fact it's central to the formation of the team as a functioning entity
) One thing that really did annoy me was he choice of villain - Loki. Now, don't get me wrong, I like the character of Loki, and I think the actor played a VERY good "comic book loki", yet I think such a huge character has VERY much limited where they can go from here. Loki is a pretty "high bar" to top, because the only way onwards is to "ramp it up" (which if you watch the credits, they DO). Then again, considering in Thor they destroyed Bifrost, they DID need a way to work Thor back into the story, and no-one is going to get Thors attention more than Loki
One thing that really did bug me was the continuity of the "big fight" In many ways I found it horribly disjointed in how they jumped from character to character and it really did drag me out of the moment. The main 2 "offenders" her are the scenes with Hulk and Thor. Again however, these two characters are 2 of the most physically powerful characters in the Marvel-verse, and to spend too much time on them may have actually detracted from the idea of a team.
Good things:
"Air time balance" - All of the characters get a decent amount of screentime. Iron Man does get a little more than the others, but I think that is more due to the fact that Iron man is more the "human lens" for us to see the team through, so that is understandable.
Humor- Plenty of LOL moments going on, mostly through Hulk and his interactions with Thor. None of it felt "forced", but it did get a bit over top in some parts. Joss went a bit too "Buffy-esque" humor where he really shoulda gone more "firefly". Again though, considering the main 2 involved, "Physical humor" works for them.
Overall Story - It felt exactly like a "visual comic book", and to me, it was well executed in that way. Was it the strongest story, no. Was it "deep and emotional storytelling", no. Was it exactly what you would find in your average marvel comic book, YES. Yes there were some serious moments and moral messages, but again, they were handled in comic book style and for me at least, it worked well.
If I were to rate the avengers as a "stand alone peice of cinematography" I would probably rate it as a solid 5.5/10, It was not outstanding, but neither was it bad. If however I were to look it as a "comic book movie", I would give it 8.5-9/10. It hit every note it should, it was a fun and enjoyable flick and if you go in expecting a "summer blockbuster" I doubt you will be dissapointed.