This release took forever because the original Blizzard North team basically left/was canned like halfway into the original D3 project, scrapped a good portion of it, changed things up drastically, and added some things. There were so many issues between Blizzard and Blizzard North....
It's sad that all the off-shoot development teams that came to life from the Blizzard North exodus have basically all closed up shop too, or simply not lived up to their own standards.
Hellgate: London was probably destined to fail since EA was at the helm

P), but I wouldn't mind seeing those devs create a new home for themselves and come up with something new.
Torchlight will likely never live up to its potential. Sure, it features most of the best qualities, but it's going to be left behind if they don't modernize it in time. They need a bigger team and bigger budget, for sure, so maybe Torchlight 3 (if such does come about) will be the title it needs. I might pick up Torchlight 2, but who knows...
But from this point on, Diablo is no longer the Diablo that was - everyone responsible is gone and lent none of their talents (iirc) to Diablo 3.
That's not to say I'm not in love with Diablo 3 - because it's crack and you can't help but love some quality crack. But it's not what it could have been - and judging by what the former talent has produced, it might not have done as well anyhow.