Normally I try to space out my blog entries, but I just noticed this and couldn't resist...
From KoKoRo: Ken Kutaragi reveals PSP specs.
The salient bits: two (?) 32 bit CPUs, 8MB memory, 3D sound, Wireless LAN(802.11), IrDA and USB2.0. Prototype at E3 2004.
Some more slides from the PlayStation Meeting 2003, including info on programming the PSP and a schematic of the CPU, can be seen here.