Somehow in my ever connected life, I missed the news on this.
Every vehicle and track from Gran Turismo 5 will be included in this game (totaling at 1,200 cars and 33 tracks from day 1 and more will be continually added online), it will also have a mobile app (didn't say for what OS) and web app to add some cross device connectivity oh and it's for PlayStation 3 (surprisingly not for the PS4).

_{While I'm glad it's for PS3, I hope they still make a version for PS4 (Maybe GT6+ or something, with online play vs. PS3s, upgraded graphics and share button support).}

(Source: Gran-Turismo.com)