Edit: there's actually a really nice breakdown of the technology over here
After the amazing Wreck It Ralph I had a lot of hope restored for Disney's animation studio, sure it wasn't hand-drawn like "the good ol' days", but it still held that classic Disney charm. There is a still a long road ahead of Disney before I'll consider them the leading studio in animation like they once were, but seeing the quality of the pre-movie short 'Paperman' (directed by John Kahrs) really started to warm me back up.
While no solid information on the technology used for the short has been given, the animation studio has used an amazing technique to seamlessly intertwine both hand-drawn and computer animation. It really becomes apparent when looking at the facial animation of each of the characters, there's just something about hand-drawn eyes and mouths that conveys emotion better than computer animation. I'm really hoping that this technology finds a home in feature length films, because Disney definitely has something incredibly special here.
Hit the jump for a few behind videos for behind the scenes