PSP
Gran Turismo (Oct 1) = untested on portables, should sell well regardless
GTA Chinatown Wars (Oct 5) = late port
Tekken 6 (Nov) = fighting game on a portable (lol)
Assassin's Creed: Bloodlines (Q4) = unlikely to sell well on a portable
Little Big Planet PSP (Q4) = modest sucess
Jak and Daxter: The Lost Frontier (TBA 2009) = modest sucess
DS
Pokemon Mystery Dungeon: Explorers of Sky (Oct 12.) = pokemon on a portable, even if not main series
Mario and Sonic at the Winter Games (Oct 13.) = the sequel to a huge game
Cooking Mama 3 (Oct 27) = decent sucess
Call of Duty Modern Warfere Mobilized (Nov 10) = likely won't sell well
Mario and Luigi 3 (Nov in Europe/Others) = the best selling mario and luigi ever in Japan
The Legend of Zelda: Spirt Tracks (Q4) = the best franchise evar!!
DS will win, hands down