So, the 2013 Mustang refresh details are out. The GT/V6 get a revised GT500-esque front fascia, new rocker panels, new rear bumper, and some nice new LED tail lights. The 5.0 gets a power bump to 420 hp from 412...
But the real story is the GT500, which gets a 5.8L supercharged V8 with a whopping
650hp and 600lb-ft, making it the most powerful production V8 car in the world. The ZL1 Camaro puts out 580hp for reference.
Even more surprising are the aerodynamic tweaks and elimination of the electronic limiter. The 2013 GT500 features a 33% increase in downforce at 160 MPH and a
top speed of over 200 MPH!!!
Hopefully soon Ford will release some Nurburgring times as a lot of the development was done there. Rumor on the street is it's quite a bit quicker than the ZL1, which I believe ran a 7:41 lap.
The suspension has been revised (includes some new in-cockpit electronically adjustable Bilstein shocks and struts) and it weighs the same as before (3,850lbs) so it should be quite an improvement over the current 2012, which is very stout in its own right.
Here's a link to the full overview of changes if you are interested:
Complete 2013 Mustang Lineup Overview | Mustangs Daily