I'm pretty sure the parts they're really chucking out the airlock have to do with the Vong and the Second Galactic Civil War and stuff in between those events, because it's a pain in the ass to write a movie script and have to heave to all that awkward and sometimes-conflicting canon. I think Abrams and the screenwriters need the ability to throw away parts of the EU that gum up the entire works. But he also has the freedom to -modify- things like Grand Admiral Thrawn. I suppose we'll simply have to wait and see.

If you really love that expanded universe stuff, it's still there -- the books can be had and Wookieepedia will probably keep chugging along.