I see it differently. Aside from gamer's wanting the next Blizzard MMO to come out, why would Blizzard release it now? WoW still has ~ 9 million subscriptions world wide. It's one of the few MMOs that is still profitable as a subscription model. Everyone else is doing microtransactions.
It was said when EQ2 came out - one of the biggest deterrents for EQ2 was EQ1 was still wildly popular and was still releasing content updates. So, EQ2 suffered. Ok, so EQ2 had some launch issues, but dig back through some old reviews for it and this comes up quite a few times. It was also said when D&D Online released that it came out a few years prior ala EQ, which at the time was a much better game.
Another example? UO2 - why this was never released amazes me. Even more so considering UO is still around. But, at the time UO2 was shelved partially because UO was still popular. I'm not sure the concept for UO2 fit the UO world, but there was helluva good marketing in the concept pitch. Still gets me stoked seeing it:http://www.youtube.com/watch?v=9XyRcFvvKFs
It will never happen, but if we want to help Blizzard put more emphasis on Titan - stop playing WoW and I'll bet Titan fires fast.