The calendar for 2010 is now available subject to a final couple of confirmations. Its on the GT1 World website, but here it is below.
03/04/10 Yas Marina
02/05/10 Silverstone
23/05/10 Brno
04/07/10 Paul Ricard HTTT
01/08/10 Spa-Francorchamps
29/08/10 Nürburgring
19/09/10 Algarve
07/11/10 Durban
28/11/10 Interlagos
05/12/10 San Luis
As for Le Mans....entry is strictly by invitation from the ACO, who will announce the invitations at the end of January. So apart from those teams with automatic entries, everyone else must apply and wait.
Hope that helps a little.