I have a 2007 as well and have experienced the same issue.
First, if you have not done it yet have your tires rotated and balanced.
I followed the instructions that Planman has in his videos on youtube. It is a little time consuming. However, you will find exactly what is causing the shimmy in your front end. Fair warning the videos are slightly lengthy but he will show every part you need to inspect on your front end.
Diagnosing Death Wobble and Fixing Non-DW Shimmies and Wobbles - JeepForum.com
I had to replace my tierod and draglink ends, replace my ball joints, and beef-up my trackbar mounts. This is obviously a worst case scenario. I do flog the crap out of mine while rockcrawling. Let me know if you have any other questions.