My thoughts on this.
-They can hardly do a worse job writing/directing these things than Lucas has. Unless they really surprise us.
-With Lucas in an 'executive consultant' position, these movies can still benefit from the best of what he may have to offer.
-As noted above, Disney hasn't screwed up the Marvel film franchise. I was skeptical in 2011 after THOR came out, but the movies have been mostly consistent. Then again, I don't know to what degree (if any) Disney might have interfered with the films creatively. Maybe not at all.
-Too early to tell what this means for the first six movies, but maybe the ones shot on film could get a proper restoration. The original negatives have been abandoned since 2004, and the films currently exist as video files at 1080p resolution. Filming technology has passed episodes II-III by, and home video technology may be about to as well. The episodes shot on film need to be better preserved than that, preferably at 4k or higher.
-Even more problematic than the above, but maybe the films could be preserved in their original versions as well, depending on the politics involved and on what film material still exists that hasn't been destroyed. I suppose ideally, all versions in between would also be reassembled and preserved. Even if they never get re-released, the option to do so should be protected.
-Do we really need more SW? The core story has already been finished as of 2005/1983, take your pick. (Though arguably we didn't really need any more ST either).
-What will be the direction with the films if they keep cranking them out? How well realized will they be? Could they start to become more episodic? Formattic in terms of setting and characters? Or even formulaic?
-Will they become too commercialized? I feel like SW is already as commercialized as it can get; that's been part of the problem. And 'good' commercialized films still get made (Star Trek, The Marvel franchise movies). I doubt we'd ever return to the quasi-independent filmmaking of the first two movies, under Lucas or Disney. Unfortunately.
-Alternatively, could SW become too over-protected? So that it starts appealing to a smaller and smaller audience of mostly hardcore fans? And could Disney try to 'fix' it by relying to heavily on what the fans think they want (for the record, I think adapting Timothy Zahn's trilogy or any other fan-oriented novel or comic book would be a HUGE mistake). This might be less of a concern with Disney than, say Paramount, since I suspect Disney is too finicky to not realize right away when things are headed South.