I doubt that Disney would screw with FFG's license, or really most licenses out there. That's how Star Wars is the cash cow it is; sure, the films have all made an insane amount of money, but it's the whole scope of the media empire which is why they'd pay $4 billion dollars. I'm sure they'll look to find ways to expand licensing opportunities, but there's no real reason to cut off existing licenses.
On the whole, I'm cautiously optimistic about this whole deal. If George Lucas had just come out and announced he was doing more films, I'd just groan and wonder what he'll ruin now. Even if Episode VII is based on a treatment Lucas prepared, it's going to be made by other people, and getting control of Star Wars out of Lucas' hands is pretty much the best thing that can happen to the franchise. Even if the new movies end up being terrible, that's just maintaining the status quo; there's no where to go but up with the Star Wars films.
I glad that Disney's has the right now. They will make a better set of movies then epi. 1,2,3. What killed it for me was that you find out that Darth Vader is Anikin in RotS. It killed the plot for epi. 5, where Luke (and you ) find out that Vader is his father. What Lukas should have done was have Count Ducoo (sp), Gen. Grevis and Anikin, (hell even a clone or the surving part of Darth MAul would have been cool.) All fall around the same time and have the Lord Sith grab them all and tell then that one of them will be his 2nd. Maybe, All where heal/fix to a point and Lord sith had each of them fight in a room to the death. We don't see the outcome because the door close. Next WE see is Vader coming out of the med/borg room. The Question about Padmai and her death could have been ask before the fight broke out IN said room.
that just my 2 cents.
So yeah I'm happy someone else is doing it. It should flow alot smother with the 1st 6 episodes now. Here hoping.