This according to Latino Review. Major spoilers... be warned!
Here's hoping that the Avengers doesn't suffer from having too many villains without focusing on any of them. That seems to be one of the major pitfalls of making a comic book movie. There is this desire to cram in extra characters, especially villains, and no one get's ample screen time and the movie sucks.
Still, in Joss Whedon I trust. I fully expect (and hope) that he succeeds and the movie is good.