If they were to add GP2 support it would likely be offered for sale as a downloadable content offering. It is doubtful that it would ever get its own game or be added to the regular F1 offering. Still, the F1 feeder series might be something that could be an option in the future if there is enough interest among players and Codemasters is able to sort out the licensing.
Codemasters is still on track to deliver the 2011 version of F1 this September. In addition, both 3DS and PlayStation Vita versions of F1 2011 are coming. The 3DS and Vita versions will be developed by Sumo Digital who handled the PSP and Wii version of F1 2009 for Codemasters. The 3DS and Vita versions of F1 2011 will follow the release of the Xbox 360, PlayStation 3, and PC versions. No timetable has been announced for the handheld versions.