Because Sony will be showing off both Gran Turismo PSP and Gran Turismo 5 (just like they did at E3) at Gamescom, Polyphony's website has been updated with a few more details on the game, along with some "images."
I say "images" instead of screenshots because they're of the game's...main menu screen, which will be using the same system found in GT5 Prologue; a shiny car, in a shiny place, with an XMB-style bar across the bottom.
Anyway...to the details!
Tracks: Around 80
Cars: 1000 (830 "regular" ones, 170 with a little more modelling, with their interiors responding to damage, etc)
Damage: Yup, there'll be damage
GTTV: GT's in-game TV show, GTTV, is back (it has Top Gear!), and this time can be ported over to your PSP
Sadly, no, there was no release date. Though come on, it's Gran Turismo we're talking about here. It'll be ready not when it's ready, but 2-3 years after it's ready.