An official build of Android 4.0 Ice Cream Sandwich for HTC's Thunderbolt has been leaked on TeamBAMF's forum. The leak is build number 7.00.605.2 and brings the Thunderbolt to Android 4.03 and Sense 3.6. The leak is mostly a stock ROM, except it has root and HTC's bloatware removed. While the release should be stable, there is no word on whether the leak is the final OTA release or not, so proceed with caution. If you're interested head on over to TeamBAMF's site for the download. If you do, let us know what you think in the forums.
Source: Phandroid