The DS owns the PSP, because of what Jyuu said. I for one, would like the ergonomics fixed. If I play some games on the PSP for a while, I get carpal tunnel. I can be on the DS for hours and not feel a thing. Games are also a thing. For every God of War, there is a Metal Gear card game (WTf?). The PSP tried to be everything to everyone. That rarely works.
Sony should just port some of the great PS1 and PS2 games. They have a built in fan base. I would buy a PSP to play Prince of Persia on subway.