Assassin's Creed: Brotherhood is a great game. The post-launch DLC that Ubisoft Montreal released alongside it is not, and the studio has publicly stated that they will aim to do better in the future.
The DLC in question consisted of adding 'cut' chapters to the single-player campaign mode. As a result, fans reportedly felt concerned that they had been cheated by the add-on content. Producer Vincent Pontbriand accepted those concerns when speaking to CVG
"We wish to [do better]. I think people felt cheated at the impression that there was stuff that didn't make it into the game. It's frustrating since I can understand that view but it wasn't our intentions at all," Pontbriand said. "We want to give more of the game so we have plans for post-launch DLC. It's a mix between maintaining shelf life."
More DLC is planned, but might focus more on the multiplayer elements than the single-player story.