Just root and install CM7...it's all the gingerbread you need! I did it a few days ago, and couldn't be happier with it. I laughed when last night's "update" came out.
Re: CM7 for Thunderbolt. RC1.1 Updated 6-30 08:51AM Now supports
Just installed it with the MR2 radio. Working great so far, and what a UI improvement over the stock Froyo/Sense!