I've never been a huge Avengers fan, but I love some of the characters on their own. This to me is going to be a major commonality that will drive huge numbers on this movie. I've been a Batman fan my entire life, but for some reason, I'm never overly excited when a new Bat movie comes out. We've seen him on screen many times now. Not so with the Avengers. This is a first, and people are really excited about it.
Now if DC can just build up a few more movies and get that Justice League film up and running, and I get the feeling that would shatter any records you could put in its path.