Ars Technica didn't seem too impressed with it.

In particular "this new iteration of the platform is what would happen if a facepalm was turned into a piece of hardware. "

That's a scathing review right there.

Personally, I think it looks stupid, the original style PSP looks much better to play and hold. I haven't seen anyone playing PSP on public transport for a long time.... if I didn't hang around on games forums I'd never have known the PSP Go was even coming - I've seen no adverts for it, there's been no attampt to build any 'heat' for it.