It's good to see you guys aren't freaking out like people elsewhere in the internet.
I'm kinda looking forward to see Star Wars handled by people other than George Lucas.
Also, Disney is going to get the special effects resources Lucas built up. We may see more of it in use through Disney's various studios. Let's just hope they don't go overboard like with the Star Wars prequels.
There's no reason to freak out. Disney is very good about not stuffing undue things in their franchises; you don't see Donald Duck creeping into Wolverine comics, and you won't see Darth Mickey in the new Star Wars.
Even more than that, Disney, through a variety of subsidiaries, owns a *ton* of separate studios that make a wide variety of moves, including horrible slasher films. With so many resources available to them, and fairly competent managerial staff, they could do a lot of good to the franchise.
Especially if they keep George 'Jar Jar Binks Was A Good Idea' Lucas out of it.