Update: Blizzard has responded to the Venturebeat story: “We’ve always had a highly iterative development process, and the unannounced MMO is no exception,” Blizzard spokesman Shon Damron said. “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.”
Apparently that means development is being restarted from scratch, and as such the game won’t be out until 2016 at the earliest.
The source also claims that the team working on the game has been reduced from 100 to 30, with developers cut from the team being shifted to other projects.
Rumours in April characterised Titan as an eSport-focussed MMO based on Earth's history that featured “a lot of time travel” and incorporated Greek, Roman, and Viking myths.
While Blizzard has never confirmed any details about Titan, commentators had expected it to arrive in 2014.