I was always excited to see what they had in store for us, but after waiting seven years and seeing minimal updates (not to mention the "back to the drawing board" approach from last year), I hate to say I'm not surprised.
Blizzard's a smart company. I'm sure they've seen that it's unlikely that they'll have another hit in the MMO space like World of Warcraft. Who knows if Titan would have been a drastically different or genre-defining experience than what came before it.
Just judging by how well most of these titles perform nowadays, it seems like the investment isn't quite worth it. I'm hopeful when I see games like Wildstar (or the unyielding EVE Online), but the genre just doesn't seem to hit as heavily with consumers as it once did. There's not enough differentiating each title from one another. Would Blizzard have been the one to create something new and innovative once again? Guess we'll never know.