I was planning to chime in with my 2 cents on "what makes a Muscle Car?" as I was reading thru this thread, but the post with the wikipedia link beat me to it. I think the banter between those 2 just showed the lack of maturity in
BOTH of them, one who couldn't recognize he was being baited and the other who seemed to be entertained by goading the other into further rants.
charged07gt - I could find it easy to agree with your opinion that the '11 V6 is not a muscle car, but if I did I would have to state that your GT is also not a muscle car. A lot of people throw around the term "muscle car" and it means different things to different people, but to those of us who were around when the original muscle cars were rolling out of Detroit the last real muscle car was built in '76, the 455 HO Firebird, and even that is debatable among some people as still being too new to be included in the group while others like to include the 400 c.i. Trans Am up to '79 even though by then they had a very weak 200 HP rating and being a 4000 lb car could barely get out of it's own way, but it was good at spinning it's 225/70 tires off the line. For most of the car brands other than Pontiac, the last year for real muscle cars was '72.
Your stated definition of a muscle car is only your opinion, and is grossly broad in scope while at the same time unreasonably restrictive. You are certainly entitled to your opinion that the new V6 car isn't a muscle car simply because is doesn't have a V8. You're wrong in saying that, but you're still entitled to that opinion. If a person is to accept the idea that any car can be a muscle car regardless of it's model year, or even it's factory original engine then a realistic yardstick to judge it by would be it's performance since that was the defining characteristic of what a muscle car was back in the 60's and 70's. And yes, they were all V8's, but that's because the technology to make 300+ HP (using todays HP rating guidelines) from anything less than a
BIG V8 engine and still be drivable on the street simply didn't exist. It took 400 or more gas sucking, smoke blowing, car shaking cubic inches to make that kind of power. 300 HP in todays measuring methods would be very close to 400 HP as it was rated in '71, and if you check it out you'll notice there weren't very many cars with that kind of power even then.
So, to end a rather long winded post I'll simply state my opinion to answer the OP's topic;
No, I don't believe todays performance cars are muscle cars, and thank god they aren't. Muscle cars smelled, rattled, were noisy (not always in a good way), and got terrible gas mileage. Plus, by the time they were just a couple years old needed frequent maintenance and often rusted out badly before they were even 5 years old.
Todays performance cars are just that, cars that perform very well. They are sophisticated, balanced, efficient, and reliable example of modern technology that out do real muscle cars in every aspect (except maybe nostalgic style), regardless of how many cylinders they use to produce their power. They may have muscle, and in some cases a lot of it, but they are not muscle cars, and as I said, thank god they aren't.
That's just my opinion though, feel free to disagree if you like.
The 2010 GT is more of a sportscar IMO...too refined and too good of a driver to be classified as a "musclecar".
and what i got from the wiki is mustangs were only pony cars in the day but terminology today has thinking hp vs model to make a muscle car vs pony. did i say that right? 
sorry just a bad head cold. 
