Not surprising that. Blizzard have a tendancy to play their cards close to their collective chest, and they don’t make game announcements until the last possible minute.
I expect that there won’t be any real details on Titan at Blizzcon 2012 either. At best it is more likely to be some form of comment made in an interview at the event rather than a presentation.
So when will Titan be announced?
Considering the late 2014 timeline we currently have, we should expect details no earlier than mid 2013. And that’s only if the game is on schedule at the time.