1 - An Unexpected Journey 2- The Desolation of Smaug 3 - There and Back Again
Spoilers about the pacing of the first movie, if you've read the book and don't mind knowing when the first movie ends it's ok to read:
The first movie ends right after the party is rescued by the Eagles. I'm guessing the second will mostly take place in Mirkwood and get them to The Lonely mountain and Dale, and in the third they will deal with Smaug and the Battle of Five Armies (duh lol). It does seem natural to make three movies, although I still think they could have done it in two if they didn't add all the extra content. I'm still not sure The Hobbit should be as long as the entire LOTR trilogy.