Continue to play WoW
While this isn't nearly enough to outright claim legitimacy on the product slate, it does provide at least a good general insight to what will most likely be the future. If this slate is correct, Titan will be released in the same quarter as the final expansion pack. This makes sense, as to be expected most of Blizzards existing and previous player base will migrate over to their new MMO. Others will remain stubborn though, and of course continue to play WoW. This however, will see the point in which that 11.4 Million figure begins to make its inevitable decline, and most likely at record levels. The game however would still receive content updates, and things are most likely pointing towards the last content patch for WoW will be in November 2014, the 10 year anniversary of World of Warcraft.
At this point it is entirely up to the community how long the game will stay live, and this truly depends on the quality of project Titan. If it turns out to be a high quality MMO, there will be no reason for most WoW players to remain in the game. On the other hand though, it could turn out to be a disappointment and lead to extra longevity in WoW's lifetime. On a side note, the 10th Anniversary will be a great time for players to get their hands on what might be the last batch of Warcraft Swag. Blizzard will go big on their last squeeze of the cow's teat, and this will probably be your last chance to get your hands on collectibles and such. So it might be a good idea to save up some cash ahead of time, if you're someone like me and like the idea of having a box of Warcraft junk in your cupboard to reminisce over fond vanilla memories.