It's a basic stock setup with all the Verizon
crapware value added software removed, based on the 1.12.605.9 RUU that has been floating around. Besides the removal of the Verizonware, the ROM is deodexed, zip-aligned, and has the latest versions of Gmail and the Android Market.
Word is that this is just to get things started, and Adrynalyne will have something special for TBolters soon. Keep your eyes peeled and visit the Android Central Thunderbolt forums for more news. [Android Central forums]