^^Isn't that all remakes/ports of old games though?
Much of it is, but, remember, Nintendo caters to the casual crowd and new gamers. New gamers never played the old stuff, and now get a chance to with the ports. I never had an N64, but I got to play Super Mario 64 anyway, just on the DS. And Square released The World Ends With You, which was original.
Anyway, I own both, love both, and agree with much that has been said. If you want to play games that are raw fun, go with the DS. As per tradition, many of the top titles are developed by Nintendo itself--New Super Mario Bros., Legend of Zelda, Mario Kart, and so forth. The touch screen allows for some occasionally inventive gameplay, and it is considerably more portable. It has a better game library, and games come out for it
considerably more often than the PSP, though most of the games are shovel ware.
The PSP gives you games that make for better
experiences but are, as a rule, less simply fun. God of War: Chains of Olympus was graphically amazing and its combat consisted of the best button-mashing ever, but clocked in at something like seven hours long. I sunk 48 hours into JRPG Jeanne D'Arc, and loved it, but it didn't give me the same goofy grin the Mario & Luigi RPGs did on the DS (okay, fine, one was really for the GBA.) Game releases are far more inconsistent on the PSP--usually one to two games come out in a month, and most are ignored. Several new games have been announced for the Portable recently--including versions of LittleBigPlanet and Rock Band--but those are a ways off. I'll often play a PSP game for a few weeks, enjoying every minute of it, before I hit a wall and simply stop having fun. I almost never reach that with the DS.