Do we have confirmation that Sorcerer is arcane? It makes sense given it's current state, but the title is generic enough that they could take it almost any direction to divide it further from Wizard.
Bard (leader) and Swordmage (defender) seem likely, unless covered elsewhere (but my preference is that the PHB and power sourcebook encompass all of the available classes for a power source), So I'm going to go with them. I could see them being the only two.
As for other power sources. Primal and Psionic are safe bets for the next set of core books. Shadow has gotten some discussion, and is likely the third. I hope martial and psionic have divided and eaten Ki. I cringe every time it's mentioned. Spirit could be interesting. Artifice/Tech could be interesting (tinkers were always fun in concept, and 3rd edition took great steps toward making them fit in better mechanically). I don't think the Artificer can wait long enough to be in the 3rd PHB, as it is needed for Eberron, so it'll either be in the arcane book as a class or path/destiny or handled as a new class in the Eberron setting guide.
Bard (leader) and Swordmage (defender) seem likely, unless covered elsewhere (but my preference is that the PHB and power sourcebook encompass all of the available classes for a power source), So I'm going to go with them. I could see them being the only two.
As for other power sources. Primal and Psionic are safe bets for the next set of core books. Shadow has gotten some discussion, and is likely the third. I hope martial and psionic have divided and eaten Ki. I cringe every time it's mentioned. Spirit could be interesting. Artifice/Tech could be interesting (tinkers were always fun in concept, and 3rd edition took great steps toward making them fit in better mechanically). I don't think the Artificer can wait long enough to be in the 3rd PHB, as it is needed for Eberron, so it'll either be in the arcane book as a class or path/destiny or handled as a new class in the Eberron setting guide.