ALMS, FORZA JOIN FORCES — Turn 10 Studios, creators of the best-rated “Forza Motorsport” video game franchise, and the American Le Mans Series will partner across a range of events and content celebrating the famed racing series as well as the launch of “Forza Motorsport 4” on Oct. 11, exclusively on Xbox 360.
As the official racing game partner of the American Le Mans Series, “Forza Motorsport 4” will provide the “Forza Motorsport” community with unrivaled access to one of the top professional racing series, including realistic in-game tracks and cars. Additionally fans of the American Le Mans Series will have the opportunity to test drive “Forza Motorsport 4” at select race events before it launches in October
http://forums.forzamotorsport.net/forums/thread/4738536.aspx
http://twitter.com/#!/almsnotes/status/99623187125501952
More info to come - should be interesting 
This is great news. As Chris and I are going to be at an ALMS race early Sept . . i imagine we may have a go at it :) we'll keep you up to datewith the latest!