For those wondering what's next for Blizzard, it's not Titan.
Titan, the often rumored MMO successor to WoW, has been officially canned by Blizz.
What I got from the Polygon article (go, read the link, I'll wait) was that Blizz couldn't recapture that elusive "it" that they had with WoW, and decided to kill off Titan before it became an albatross and dragged down their reputation. Does that mean that even Blizzard can't put out a new MMO in this climate that will potentially topple WoW? Probably, but that's not their stated goal. Does it mean that it can't put out a new MMO that will at least be successful and not hemorrhage subscribers after a few months? I think that more likely.
If that doesn't give the MMO market pause, then I don't know what will. Even Blizzard is admitting defeat before Titan was even released.
The article also tells me that WoW is going to be the last word in the MMO genre from Blizzard. No Starcraft MMO, no WoW 2, nothing. What you see in WoW is what you'll get; some incremental updates, some new expacs, some other stuff from other MMOs (housing) added on, but at its heart WoW is going to be the MMO you see today.
I also suspect that the rise of League of Legends and other MOBA games has had an impact here as well. Video game professional leagues have suddenly become big business, and money is flowing in that direction. Releasing an MMO when the money is going elsewhere isn't smart business. Of course, you can lose your way merely chasing the money; a AAA video game is often years in development, and where the money is at when you start development is not where it's at when you're finished.*
Finally, expect more small tie-in titles in the future, such as Hearthstone, but leveraging their existing Blizzard properties. It is entirely possible that Blizz isn't going to create anything new, such as completely original games with new worlds and/or properties, for a long time to come. Creating a new, original property takes some risk, and Blizzard seems to be electing to go the safe route and reuse the properties instead.
To be honest, Blizzard has been living on its existing properties (Warcraft/Diablo/Starcraft) for a while now, and Titan was going to be a fourth leg of a table. I guess that table will have to get by with three legs now.
*See: novels and movies. The time it takes for a novel to be written and then published is a couple of years --and movies even longer-- and tastes can change at the drop of a hat.