IIRC, development costs for the DS is on average 400,000, while 800,000 on the PSP. Given how a big-name PC game can go in the millions (which I guess NWN2 goes into, or any would-be CRPG with high production values), or tens of millions (what was the estimate for next-gen titles, 10-30 mill?), that's quite a difference. You can only hire so many designers and writers with all that money. I'd rather devs spend time focusing more on design/gameplay/story more than in the technical aspects of a game. In that sense, doing some handheld on the side can be quite beneficial for both parties.