Looks like the third trilogy is going to be an original work. I'm sad. Not because I think Disney will do a shitty job, but because I was realllllly hoping for an adaption of Timothy Zahn's Thrawn trilogy. It is without a doubt some of the best material in the Star Wars universe, and I've always thought that if anything deserved its own adaption for the big screen, that collection should get first dibs.
Mark Hamill said something that made me lose some of my doubts for the 7th movie. He basically said that while a lot of people are nervous about Disney, they did a pretty good job with the Avengers universe and Pixar collection. And I guess the Muppets, but that's not really in the same league. It will really come down to who ends up directing the film, who ends up writing it, and how much input George Lucas still has in the creative process.
In my opinion, he shouldn't. If you need any more proof than the second Star Wars trilogy, just go ahead and re-watch Indiana Jones and the Crystal Skull-fuckery.