The lengths that fans, writers, artists, and licence holders go to to maintain continuity within comic universes (along with the related Sci-Fi and fantasy universes such as Star Trek, Star Wars, and Doctor Who) is remarkable. The recent spate of Marvel movies including Iron Man, The Hulk, and next year's Thor have shown how universe continuity can be maintained in cinema and create innovative sequels/crossovers. Whether or not they work for the general public is yet to be seen. I personally love the Avengers super-hero team but is the world really ready for cinematic versions of AntMan or the Wasp?
I guess we'll find out over the next few years but for now lets enjoy a musical ribbing of the whole phenomenon.