Although Woz and some others might not think highly of the HTC Thunderbolt, there is still a lot of folks out there making use of the device today. Verizon and HTC are preparing an Android 4.0 Ice Cream Sandwich update to appease the masses but if you simply cannot wait you now have another option available. Team BAMF has gotten ahold of the official Ice Cream Sandwich ROM for the HTC Thunderbolt if you're feeling adventurous.
The ROM is marked as build number 7.00.605.2 and includes Sense 3.6 as well as some new styling changes and the inclusion of the 'Quick Settings' tab. One thing to keep in mind is the that if you're rooted currently and want to stay that way, you'll want to avoid this for now but if you care nothing about all of that, you can jump right in and give it a go.
Just remember, 'official' in this case isn't really official from Verizon sent via OTA so there may be some unknown dragons ahead. Also, the team BAMF site seems a little under pressure at the moment so you might want to wait for some mirrors of the file.
Source: Team BAMF