Way back in the day, a race car driver name Carol Shelby modified some Ford Mustangs, and called them Shelby Cobra Mustangs (or whatever permutation you like best), in both the GT-350 and GT-500 models (these cars have interesting histories also, but that is beyond the scope of this entry). Sometime around the early '90s Ford created the Special Vehicle Team (SVT) and brought the Cobra name back to the Mustang with the '93 Mustang Cobra, and basically since then the Mustang Cobra has been the top version of the Mustang. The new 2005 Mustang, however, has no Cobra model. However, there was talk that Carol Shelby would once again put his name on a Mustang, and that has become a reality for 2006 (in car years, that means this fall).
"Hey, Gramps." "Hey, kid."
So let's see, the new Mustang gives us the most powerful V6 Mustang ever (afaik), most powerful GT ever, so what does this GT-500 give us? Yep, the most powerful production Mustang ever created. Using a tuned version of the engine found in the 2000 SVT Cobra R, this baby is powered by a supercharged 5.4 liter pushing out 450 horsepower and equal torque! I can't wait to see the performance numbers for this thing. And before anyone says "I can't wait to see the gas mileage for this thing.", I'd just like to point out that nobody pretends this is going to be a daily driver.
They say they're going to try to keep the price in the 30 thousands, like previous Mustang Cobras, but I'm going to go ahead and guess that you won't be able to buy them for that. They're even having trouble keeping up with demand for the GT's, and I don't know how many GT500s they plan on producing.
Here's a link for more information (and quite a lot) on this car.