End of May?
Id expect to see Halo 3 before a PSP, Sony have already confirmed that it wont make it to these waters until at least June, which translates to September/October, and thats being generous.
I have an idea, instead of waiting for that lump of coal to arrive, why not go out and get yourself a shiny new DS for half the price. :) Btw, just got Yoshi Touch & Go! last week, its menacingly addictive and pure nostalgic.