I was just at the dealer yesterday for some warranty work and noticed they had a new 2013 Trailhawk sitting in the showroom. I climbed under the front of it (as you do) and had a look at the tow hooks and the belly pan.
Unfortunately the tow hooks on the 2013 Trailhawk are not compatible with the 2012 models. The frame horn on the left front is further back than on the 2012. I'm not sure what other changes were made to the frame, but the service and parts department both had a look and confirmed the 2013 Trailhawk hooks will not fit on the 2012 models.
On the positive side, the 2013 Trailhawk comes with a new improved belly pan that can be put on 2011 and 2012 WK2s.
For those who aren't aware. 2011 & 2012 WK2s have a plastic belly pan (directly underneath the radiator). For some reason Jeep doesn't provide a steel skid plate to replace the belly pan?! And since it is at the front of the vehicle and it is plastic, they break quite easily when off road. The service manager told me he has already had 1/2 a dozen come in with broken ones. I broke mine while up at Fraser Island. Unfortunately the belly pan also holds the wheel well liners in place, so if it is broken the wheel well liners tend to suck out into the wheel.
The new belly pan on the 2013 Trailhawk, is made out of some material similar to the wheel well liners. Moulded into position but still flexible, so it won't break. Sadly they cost $467, but at least I don't have to install another plastic one, which I know will only break again.