Here is the link to the recent road/track test to Motortrend's YouTube review.
http://www.youtube.com/watch?v=hbdhNc_36Kc
I love my Mustang (and would love to challenge and lose to a Z/28), but this thing is out of the Boss's league. The Boss was targeted between the GT500 and the GT. Ford isn't bringing the Boss back, but I am sure a track targeted edition is coming out but not at the level of the Z/28. Don't get me wrong, I still love the ponycar wars that are going on and can't wait for Ford's response but I'm sure the GT350/Mach 1/SVT Cobra or whatever the top dog is going to be called is targeted straight at the ZL1 for all around performance.
I think Chevy did this just to flex their muscles and give a last hurrah to the LS7. This Z/28 challenges the GTR, which is regarded as the giant killer (at $115k+) so to me the Z/28 is a bargain.