Originally Posted by Heretic
These two studios could give us fans something really cool by simply agreeing to one actor for the role. The likely fact is that Bryan Singer is shoehorning the character in just to do it. He even made the announcement by name-dropping Avengers in his tweet...so clearly he is hoping that Avengers interest helps the next X-Men film, while also being the "first" to have Quicksilver (so if the character breaks out in Avengers then Fox can hype up his cameo). It sucks because I'd love just a bit of hope to some day see an Avengers vs X-Men film (even though I know it won't happen).
Days of Future Past hits theaters a year before the Avengers sequel, so Fox won't be taking advantage of Quicksilver's potential break out.