The reason it isn't coming out for the older generation gaming
systems is because it is a marketing scheme to try to get people to
buy the more expensive game systems, and I have heard people buying
a PS3 only for GTA IV. I suggest you get one somehow, steal it if
you have to. This game is going to set the standards for the next
10 years.
It's hard to believe something that uses an Xbox360/PS3
processor to work can be brought down to PSP level. And, even if it
does, I doubt the graphics would be as stunningly realistic as
playing it on an Xbox360/PS3.
It's my guess that it'll end up like liberty city on PSP, a
total mess. I get giddy just by walking.