Disney has created a new digital library for their movies. To help promote Disney Movies Anywhere, you can currently get a free copy of Wreck-It Ralph. Disney Movies Anywhere will allow you to watch your favorite Disney, Pixar, and Marvel films on any compatible device.
If you purchase a physical copy (DVD or BluRay) of most new releases movie, there should be a code which can be redeemed for the digital copy. This will allow you to take your favorite Disney films anywhere.