I saw the second trailer for it... Shit looks ill.
And they've licensed music from the late 90's to use. The music for the trailer is the mobb deep - shook ones instrumental.
http://media.psp.ign.com/media/723/723575/vids_1.html
^ Watch the second trailer.
graphics look as good as vice city... Voice acting and shit is done really well. This is probably going to be the PSPs killer app.