When Disney bought Lucasfilm over a year ago, the only real purpose was for the Mouse House to get its hands on the "Star Wars" franchise.
Lucasfilm did control one other highly valuable property though - the "Indiana Jones" franchise. However, Paramount had a controlling interest in that film series. Not anymore it would seem.
Disney and Paramount have reached an official agreement that gives Disney control over all future films in the franchise. Paramount retains rights to the first four films, and will receive a "financial participation" on any future films that are produced and released.
This clears the way for a new fifth installment, be it another sequel or even a possible reboot. However, there's no fifth film said to be in the works at this time. All those involved - Ford, Spielberg, Lucas - have all previously expressed interest in returning though.
Source: Disney & Paramount