This has been the case for quite some time and anyone who paid attention to Blizzard, would know this. I'm pretty sure this is not Team 3 based on the observations following statement by Franke Pearce. But who knows? To me, this is either a second generation World of Warcraft or an entirely new franchise (both being something which I’m personally more interested in, than some Diablo 3 MMO).
Blizzard generally responds to the question about sequels, as it being the means necessary for achieving something which their current technology cannot. That being said, they've hired people for doing physics in a MMO constrained environment. What this could mean concerning the game play, I cannot say, but surly they got something interesting cooking. End hype.

Release Starcraft2 wait 2 years release World of Starcraft. and join both FPS and MMO's and even RTS elements rather than a ever quest reskin like wow .
Its the only platform blizzard has not touched. And u never here their devs shut up about how much they love battlefeild1942-2- etc...

Diablo is from the 90's its style is 2 dark/hardcore to sell.
Diablo would fit nicer in a cinematic console game.

"Team 3" was at blizcon called Medusa.. ei queen of blades. .. blizzard will follow the exact formula of WC3 and WOW to SC2 and WOS... and reap the moneys ...

Are you serious? Do you really think Diablo 3 is too "anything" to sell? God you're talking about one of the most popular and best selling game of all the time here. And most awaited sequel too.

BTW, i do hope this new MMO is not Diablo related, I think Diablo will always give his best the singleplayer/battlenet way