I don't think there's a need for an IROC. I'd hate to see the Camaro have a million different sub-models like the new Mustang. The Mustang's "special" models are ludicrous. GT, Cobra, Saleen, and Standard. That's all they needed, but they have 2 Different Shelby's, a "Boss", a "Roush", a "California Special Edition," among others.
Personally we just need an RS, SS, and Z-28. I don't see any reason to make special editions that would cross into the Corvette Price range. The Mustang is the only thing Ford really has. But as soon as a Camaro crosses into $40K, there's no reason NOT to buy a vette.