From the studio's development blog:
"Will there be any more DLC for Fable II?"Thus far, one bit of game-expanding downloadable content has been released, the $10 Knothole Island add-on. Rumors of Fable 3 emerged earlier this week when British talk show host Jonathan Ross said he and Charlie Brooker been asked to voice characters, but it's possible that Ross confused new content with a new game.
The answer is quite simple;"Yes".