A couple of more questions answered via @Diablo’s twitter feed today.
hey, both my brother and I are huge fans and we were wondering how the new b.net will support two people playing at once.—SeriousBismuth1
If you want to play at the same time you’ll need two Battle.net accounts, and two copies of the game.—Diablo
Does Diablo 3 use the same graphics engine as StarCraft 2? Cause StarCraft 2 looks amazing!—Vulcaino
No, Diablo III uses its own custom engine. But yes, StarCraft II DOES look amazing!—Diablo