The first casting calls for X-Men: Days of Future Past state, pretty plainly, that "most of the film" will be set in 1973. This means a gap of over ten years since the events First Class.
Meanwhile, we've been led to believe that the "future" sequences will be set in the present day - albeit an alternative version of the present day. The kind of alternative present day where Mr. Strickland comes striding out onto his porch with a shotgun... if Mr. Strickland were a giant robot and the shotgun were a laser claw.
This arrangement is a reverse of the original comic that had the X-Men's future in the future and the "past" be the present. There really won't be any missing the metaphorical value in the "future" bits now.
Singer yesterday tweeted out this image of a set model. I don't know what this building is, or will be...
X-Men: Days of Future Past will be filming from April through to August.