the DS has been outselling the PSP two/three to one most months, which has defied all analyst's expectations. third parties have been scrambling to re-align their portable lineups and reportedly sony has been rebuking (read : firing) the execs in charge of the PSP launch. bottom line is, most people don't want to pay close to $300 for a handheld system, regardless of its ability. TurboXpress anyone?
don't get me wrong, PSP is a cool unit, but nintendo knows the portable market better than anyone and there has yet to be a sales equal - game gear, lynx, n-gage, neogeo pocket, turbo xpress, etc. people that buy portable games typically want a quick fix type of game, nothing so complex as sony seems to think is needed.
plus, there are a few companies thinking of developing an engine management/diagnostic interface for the DS, would be cool...