OK, so I just saw the new/extended Hobbit trailer, and I'm all peeved. Because in it, Thorin says, "We shall take back Erebor!"
Which is totally wrong! The Dwarves were a company of 13: their only goal was to steal back some of their inheritance which Smaug had stolen. The days of the great dragon-slayers were over, and they had no power, no army, and no hope of defeating Smaug. They just wanted to get in and out quietly and quickly, and get as much gold and gems as they could.
That they did, in fact, cause the end of Smaug and the revival of Erebor was a completely unintentional result. Thorin is a (mostly) practical Dwarf, and he knew better.
Oh, PJ, why do you do this to me?