Blizzard has set the release date for Diablo 3 and you can now pre-purchase your copy. As noted before though, PvP will not be there on initial launch, but will later be patched in.
http://us.battle.net/d3/en/blog/4612389/Test-3_16_2012 (http://us.battle.net/d3/en/blog/4612389/Test-3_16_2012)