That’s the branch of Blizzard that made the Diablo games. Two posts that I see take this to mean different things. Gamebiz seems to think this puts the idea of a Diablo 3 in doubt. Nooo! But. Gamespot takes the opposite view, as their headline reads “put on ‘unannounced project’–likely Diablo 3″
I’ll prefer the latter option, since I’m eagerly waiting for another Diablo.