Just so you all know, all of these tracks have just been confirmed as being on FM3:
Mazda Raceway Laguna Seca, USA
Mugello Autodromo Internazionale, Italy
Nürburgring Nordschleife, Germany
Road Atlanta, USA
Sebring International Raceway, USA
Silverstone, England
Suzuka Circuit, Japan
Tsukuba Circuit, Japan
Road America, USA
Twin Ring Montegi, Japan
Blue Valley Raceway, TBA
Camino Viejo de Montserrat, TBA
Ladera Test Track, TBA
Maple Valley, TBA
Brands Hatch, England
Monza, Italy
Knockhill, Scotland
Circuit de la Sarthe, France
Nürburgring GP, Germany
Limerock Park, USA
Circuit de Spa-Francorchamps, Belgium
Daytona International Speedway, USA
Virginia International Raceway, USA
Mount Panorama Circuit (Bathurst), Australia
Ebisu Circuit, Japan
Circuit de Monaco, Monaco
Mid-Ohio Sports Car Course, USA
Autódromo José Carlos Pace (Interlagos), Brazil
Mosport, Canada
Toronto Street Circuit, Canada
Irwindale Speedway, USA
Circuit Park Zandvoort, Netherlands
Autodromo Internacional de Curitiba, Brazil
Thruxton, England
Dubai Autodrome, United Arab Emirates
Watkins Glen, USA
Miller Motorsports Park, USA
Homestead-Miami Speedway, USA
New Jersey Motorsports Park, USA
Barber Motorsports Park, USA
Circuit Gilles Villeneuve, Canada
Nikkō Circuit, Japan
Meihan Sports Land, Japan
Sportsland SUGO, Japan
Fuji Speedway, Japan
Autopolis, Japan
Okayama International Circuit, Japan
Englishtown Raceway, USA
Infineon Raceway, USA
Autodromo Enzo e Dino Ferrari (Imola), Italy
Masaryk circuit (Brno), Czech Republic
Circuit de Nevers Magny-Cours, France
Hungaroring, Hungary
Donington Park, England
Adelaide Street Circuit, Australia
Toyota Grand Prix of Long Beach, USA
Circuit Paul Ricard, France
Phillip Island, Australia
New York, USA
Rio, Brazil
Alpine Ring, TBA
Tokyo Street Circuit, Japan
Original Test Track, TBA
Fujimi Kaido Down Hill/Hill Climb, Japan
Pacific Shipyards TBA
(mumbling) I hate the fact that the xbox 360 have this damn game