Got mine last night delivered from that well known high street store. First impressions:
GFX pretty good upgrade over FO2, bit more of a gritty look to them. Runs v well with 8x AA (that's the max) on my 4870 and AF slider about 1/2 way up.
Played the first few tracks and enjoyed having 11 cars to race with vs 7 previously but obviously a bit disappointing that the tracks are all identical to the old version - I knew this was the case but still!
Is a new time trial mode when you're doing the career - 1 lap, no nitro no other cars which was good for a bit of variety. Apart from that it all looked much the same as before - same car upgrades, cups etc. Think there's a few new cars but haven't got that far into it yet.
Hate the new music. Much preferred the old tracks but personal preference I guess!