I'm not sure if Disney wants to own anything and everything or if they just want to own anything ever touched my George Lucas. Either way the big news of the day is Disney buying the marketing and distribution rights from Paramount Pictures for Indiana Jones. They already owned some of the rights for the franchise, acquired when they bought LucasFilm, but now this allows Disney full ability to make future films if they choose so.
I think this is a good thing. The Indiana Jones franchise isn't pure anymore anyways thanks to that horrific fourth film and that's something movie fans will have to live with. Nothing stays the same forever and a new film won't necessarily be a bad thing. Disney already has been putting their best foot forward when it comes to Star Wars so I imagine they understand, at least somewhat, what these franchises mean.
Just remember that this doesn't "ruin" anything. This franchise has already given us some wonderful films and I just look at this as another shot at recapturing the magic.