http://www.virtualr.net/gran-turismo-5-officially-announced/
Cars
1,000 vehicles
170 Premium new models (full interior modeling, the interior corresponds to vehicle damage)
830 standard models (some are from Gran Turismo 4 that have been carried over to GT5) (Cars we have seen in GT4 before)
Tracks
60 tracks confirmed with 20 or more to be revealed
Vehicle Physics
Physics system simulation is brand new
Represented is full fall in vehicles (possibly rollover)
Damage representation (reproduced in full by real-time collision deformation)
Faithfully reproducing the behavior of electric cars, i.e. Prius, Insight, hybrid cars and the latest Tesla model
Arcade Mode
Single Race
2 player battle
GT Mode
World Map
My Garage
Car Dealer
Tuning Shop (parts, tires)
Car Washes/Oil Change
Race Championship (Series system, point system)
License Test
Online
Open Lobby
Text / Voice Chat
Private rooms
Online Photo Album
Online Replay Album
YouTube replay output
Photo Mode
Photo Drive (Circuit)
Photo stage (Stage Photo mode only)
Gran Turismo TV
Video output to a PSP or PSP Go®
Progressive Download
Improved user interface
Continuous Play for videos