They just shelled $4 billion out for this title. They want a return on that investment. Movie sales will not earn them a sufficient return. The way they are going to get a return on that investment is by selling toys and video games. The best market for these will be children. Therefore their target audience will be children.
The a big audience for Star Wars is nerds and nogstalgia. They probably wouldn't do something stupid like make the movies primarily for kids, since it would cut into their long term profits (and you have to remember, Disney cares quite a bit about their profits).
They will do a bunch of merchandise, but probably not that much more then there already was, there are tons of star wars stuff out already: light sabers, costumes, clothes. A new movie will allow new merchandise, but its nothing that didn't happen under the older movies.
The Avengers made Disney a billion dollars in the box office on its own. A good star wars trilogy can easily make a billion each movie (if they are really good they can make significantly more), with another few billion on merchandise for it. That's over 4 billion right there, and that's not even counting all the other money that Lucas Arts is already making (which is probably small peanuts to a company like Disney, but its still there).
Although I like the idea of new SW movies, I'm not too sure what direction Disney will take the franchise. EU storylines tend to be rather grim with the New Republic fighting all the splinter Imperial factions and the new alien threats left right and centre (YZ and the Yevetha were a handful of alien threats). Also, with the penchant for happy endings, I don't know if we'll be seeing more movies in the vein of "throw the Sith into lava".
I don't think Disney will really care about the EU, although if we are lucky they will avoid trampling all over it.
FAKE-EDIT: Stupid browser, I though I posted this ten minutes ago.