Just tried the Gameboy emulator for the PSP which is mentioned here and although it's a bit slow with no sound, IT WORKS! Sadly it's only for Japanese v1.00 PSPs so far but it bodes well for homebrew and emulation...
very good news for psp emulation then!!! already within months the psp can run emus, you can tell the psp is going places!!! this is really exiting....