UPDATE: MMORPG.com reached out to Blizzard Entertainment and received the following in reply:
Thanks for reaching out to us.
We've always had a highly iterative development process, and the unannounced MMO is no exception. We've come to a point where we need to make some large design and technology changes to the game. We're using this opportunity to shift some of our resources to assist with other projects while the core team adapts our technology and tools to accommodate these new changes. Note that we haven’t announced any dates for the MMO.
This year's Blizzcon attendees hoping to finally hear more about Titan will be disappointed to hear that the project has been rebooted and is now looking at 2016 for release. Games Beat claims that a "source close to the project" gave them the information and that seventy of the one hundred employees on Titan have been reassigned to other projects for the time being.
Read more at Games Beat.