Patrick Stewart and Ian McKellen returning for <em>X-Men: Days of Future Past</em>Last month, we reported that Bryan Singer has signed on to direct X-Men: Days of Future Past, after Matthew Vaughn dropped out. Today, the filmmaker dropped a bombshell on his Twitter account, confirming that X-Men stars Patrick Stewart and Ian McKellen are returning as Professor X and Magneto in X-Men: Days of Future Past. He also confirmed that James McAvoy, Michael Fassbender, Jennifer Lawrence, and Nicholas Hoult are returning.

Naturally, this revelation poses many questions, such as how will the older Professor X and Magneto exist alongside the younger versions played by James McAvoy and Michael Fassbender? Here's what Bryan Singer said, when asked that very question.

"The movie is called X-Men: Days of Future Past, use your imagination. More to come."

We reported earlier this month that production will begin on X-Men: Days of Future Past in April 2013.