There has nothing completely confirmed about the script of The Hobbit films, except that there'll be 2 movies, and besides the basic story from the book they'll include some references to the White Council and the Battle against the Necromancer from Dol Guldur (revealing that it was no other than Sauron). That, with the proper development, should be enough filling between both sagas, I don't think ther is much more to tell about how they connect, specially since a lot is said in LotR trilogy about Bilbo and the founding of the One Ring.
My guess is that the first movie of The Hobbit will end in the Mirkwood, after Bilbo has rescued the Dwarfs from the spiders and find out that Thorin is missing, maybe showing him prisoner of the Elven King.
So, I think Barrels out of Bound will be a set form the second Hobbit movie.