The ATCC was better under Group C/A rules prior to 1993 when they made the 2.0/5.0L split to drive out Nissan in the first place. The best thing they could do is open it up to Class A-E racing once again under Group A reg's. This would give all manufacturers a chance to showcase themselves. It's a shame TOCA didn't last long after the 1997 break up.
Toyota was never a force in the ATCC, but Godzilla destroyed pretty much everything, so it's no surprise to me that Nissan would spearhead breaking into the current 2 horse race.