Pontiac's weak attempt at bringing the GTO back was an utter failure. They took an australian car, shipped american engines overseas to be installed in them, and then shipped the whole package back to the US and guess what - no one wanted it because it looked like a holden with an arrowhead emblem on the front of it. The irony of this is back in 1974 when Pontiac discontinued the X body based GTO, it was because GM decided to begin shipping these cars with Buick V8's and the brass felt that GTO enthusiasts would not be receptive to a Buick powered Goat.
Meanwhile, Ford had the right idea and retro styled the mustang to look like the late '60s models, and they made it somewhat affordable. Dodge followed this with the retro styled Challenger. They appealed to those who missed the old muscle car era styling and power. It takes more than a badge with a name on it to accomplish this appeal, which is what Pontiac attempted to do.
I doubt the Firebird will return due to the fact of dealer politics. Its the same reason the Corvette based Pontiac Banshee was never produced beyond the concept car stage. On top of that, GM is rumored to be seriously considering dropping the Pontiac line all together.
