Actually the 2011 V6s WILL be as fast as the 05-10 GTs. There is a video of a v6 racing a 2010 GT, and the GT won... but only by a car length. And you have to remember a few things:
1. A girl was driving
2. It was an automatic
3. It didn't have the 3:73 gears
4. No performance package
The 2010 GT's 0-60 is rated around 5.1-5.2 sec. The new v6 with the performance package is rated at 5.1 seconds.
So yes the 2011 v6 performance pack is just as fast as the 2010 GT, even better on corners.