Oh, bull. PSP is just as good as DS. I know because I have both.
I've had my DS for damn near two years now, and all I've heard is how great such-and-such game is only to be disappointed when playing these so-called AAA titles. As of now, most of the titles that wow me on DS aren't even popular games (except for Phoenix Wright and FFIII).
The DS's library of games is pretty overrated. The best defense that non-PSP-owning Sony-slammers can come up with as of now is that "DS has an insanely good game library, better than PSP's," which is pretty much a lie, as both handhelds have their good games and their bad games.