quote from a really cool FalkenALMS PR dude that visits ten-tenths.com
guess that answers teh gt3 dry-sump question as well. Awsome that the 911 will continue to carry the Porsche banner in GTE

Official answer, fresh from Andy at Porsche Motorsport PR:
An announcement about the 2013 Porsche 911 GT3 RSR will be made sometime in the early fall, but it is safe to assume that it will not be based on the current 997 chassis or drivetrain.