X-Men & Avengers CROSSOVER news and Marvel Avengers: Age of Ultron casting news

Joss Whedon was recently asked about his thoughts about the possibility of an  X-Men and Avengers crossover movie.
Anyone who has read the comics will know that it has happened and that both teams share on many occasions the same nemesis
When asked about a possible crossover Whedon states "“That’s not the plan. It would be cool but I think right now I already have a ton of very talented actors in my movie playing a ton of characters, and I’m about to add a few more. So I’m not like, ‘How can we get more licensed characters because I want to kill myself and make a nine-hour movie."

For all you Avengers fans out there, the casting of Elizabeth Olsen as Scarlet Witch has to be a pretty interesting announcement.
Not because Elizabeth Olsen is cast, but because the famed comic book villain-ess  Scarlet Witch will be in the film.
Best known for her association with The Brotherhood of Evil Mutants,  Scarlet Witch is twin-sister to Quicksilver and (in the comics) she is a well known nemesis to the X-Men more-so than The Avengers...

I for one, would certainly not bet against studios working together to bring you a crossover film in the future.