The benefit is that it's smaller and lighter. That's pretty much it. It lacking UMD is the downside regarding the old titles but to a large extent Sony is targetting new owners the most (plus the obligatory tech enthusiasts).

And you are not alone lacking access to the PSN store, Sony has been exceptionaly dumb regarding PSN cards in Europe (and even in the US they arrived rather late).

The 2000 ownz...

so what going to happen with people's game library if the want a psp go? thats the only thing holding me back from getting one

FIXED

Any game that runs on the PSPgo will be able to run on a memory stick+psp3000.The media center that will come on go, will run in the psp3000.
From what we been told so far the specs are the same.

There was something about being able to use the XMB during a game for the PSPGo, not sure if it was a rumour or a certainty. Doesn't really make much of a difference to me anyway.

For me, I already have a PSP3000 and to be honest a Go will just be a pain in the butt. If I can get all of the Go content for my 3000 and the hardware isn't drastically different infact it lost the analog and yes it shrunk in size but I already own ten PSP games, none of which I could play on the Go.

So there are way to many negatives to getting the Go. And as others pointed out without a credit card buying points is very difficult outside of the US where they can purchase PSN cards!

Whats the difference between the 2000 and 3000?

Different screen and the 3000 has a mic.

the 2000 has a much better screen than the 3000, the pixels are vertical instead of horizontal.