Kingdom Hearts 358/2 preview at 1-up.

"OK, let's get this right out of the way: The title of the new DS-based Kingdom Hearts game, revealed today in Square Enix's TGS 2007 "closed mega theatre," doesn't make a damn lick of sense. Kingdom Hearts: 358/2 Days? Does that mean it's 358 days divided by two? Why not just call it "174 Days"? Or does it mean 358 of something or another in the space of two days? That would almost fit, given the way Kingdom Hearts II's prologue was divided into days....

And like the opening hours of KHII, 358/2 Days focuses not on Sora and friends but instead on Sora's Heartless, Roxas. Or more specifically, it focuses on Roxas' comrades, the mysterious Organization XIII. Unlike previous KH titles, the DS iteration adds four-player coop to the mix -- so while one player will likely want to control Roxas while others take command of Axel or other Organization XIII members."

Full Source: 1-up