Check these pics out from Stangnet.com. Looks like they are mostly changing the front of the car.
http://www.stangnet.com/Ford-Mustang-News/2009-Ford-Mustang-Spy-Shots-070119.html
http://www.stangnet.com/Ford-Mustang-News/2009-Ford-Mustang-Spy-Shots-070119.html