Blizzard explains what happened to Titan
 

If you ever wondered why Blizzard cancelled Titan, the follow-up to World of Warcraft, the answer is pretty much why you might have expected – nothing worked at all.


This was a little surprising given that in 2010, Blizzard announced that it had a team of crack developers working on an MMO that would prove to be the successor of the highly popular World of Warcraft. However in September 2014, however, without any reasons given the studio announced that the game had been cancelled. It went on to support WoW with regular updates.

http://fudzilla.com/news/games/40521...pened-to-titan