During a StarCraft Lore panel at BlizzCon 2007, Blizzard's Chief Creative Officer Chris Metzen confirmed that the company, at least as of right now, is not developing World of StarCraft. He said the idea of creating an MMO based on their popular RTS franchise has certainly been discussed at Blizzard, but no steps have actually been taken to create the game.
The World of StarCraft buzz was produced largely by internet speculation, which intensified around the time of Blizzard's Worldwide Invitational event in Seoul, South Korea, where Blizzard announced StarCraft II.
While it was really obvious, its still a bit sad for me because IMO, StarCraft has a much more interesting and deeper universe (Its the whole universe / galaxy) and while I love Arthas & Illaden, there is quite nothing and nobody as kool and as big as Kerrigan, Jim Raynor and Fenix.
Just because he says they have nothing in development dosent mean there acctualy is no W.O.S in development.
WoS starts development next year and comes out 2011-12, WoW will be or will start to be on the decline by then, and I would think Blizzard is smart enough to not make a WoW2. Move on and use SC as the next huge MMO.