It's going to be a monumental task for Blizzard to one-up themselves. They came out with the best and biggest game this side of the Call of Duty franchise, with subscribers who buy the game again every 4 months (@14.95/mo), with a bonus 4 months added with every expansion they pump out. They had the perfect formula and it came together beautifully.
And then they got lazy. They decided they were infallible. The very fact that you can claim to have a "dream team" of designers tells me that they weren't even considering failure to be a possibility. They were living a dream alright, and Diablo 3 woke them up.
How could Diablo 3 fail? The last game was a monumental success, it's been years since it came out, the fans are drooling for a sequel - it's a guaranteed winner... until it wasn't. They changed the magic formula. They added a corruptable cash house, they completely changed the art style, they streamlined it and dumbed it down in the name of a broader audience. The game itself predicates its play on you playing through it multiple times, which is harder and harder to get gamers to do with the plethora of options out there.
And dammit, it just didn't feel like Diablo - it wasn't dark, it wasn't gritty, it wasn't EVIL enough - for gods' sake, you had one of the Prime Evils leaving you diary entries. The Diet Coke of Evil - just one calorie, not evil enough. Path of Exile was and will be a success because it made that magical Diablo formula work, and in a F2P model at that.
Blizzard has realized they can't just poop into a mold and call it a birthday cake anymore. They can't just rest on their laurels. The Azerothian Empire will sustain them for now, but their dominion is on the wane and they need creativity and genius again to remain relevant. But they're not agile anymore, now they are 100x larger, with more suits than a Men's Wearhouse sticking their permanent pressed lapels into every aspect of the game design.
So I don't doubt what came out into Alpha from project Titan was a misshapen afterbirth of a marketing-mutated CHUD baby. At least they had the good sense to put a pillow over it and start again, but going back to the drawing board at this stage of the game does not look good. Inventive game design is born with an idea that drives the creative machine, that idea guides the hand of all of the design, mechanics, art, rules, and acts as the very soul of a truly good game. I have a feeling that there is no solid core to this project, and it will end up being a pasted together clone of other people's ideas. AKA, a beautiful, epic, heavily marketed mediocre game.