Bryan Singer is currently working on X-Men: Days Of Future Past in post-production where he tweeted the following image that seems to suggest Xavier's School gets into some trouble in the movie.
We see the sign is on the ground almost covered by grass; however, the grass really isn't all that long suggesting the sign hasn't been there a while, but may have fallen instead.
It could be the sign falls as a result of some rumbling or fighting that goes down at the school.
With X-Men: Days Of Future Past coming out next May, the first trailer should be here shortly; possibly November or December is our guess.
"X-Men: Days of Future Past" has a May 23, 2014 release date starring Jennifer Lawrence, James McAvoy, Michael Fassbender, Nicholas Hoult, Anna Paquin, Ellen Page, ShawnAshmore, Hugh Jackman reprising as Wolverine, returning cast members Patrick Stewart and Ian McKellan, with Peter Dinklage as Bolivar Trask.