The SDK port for Ice Cream Sandwich was seen yesterday for the Nexus S and today PhanDroid reports that the Thunderbolt is getting a little love to. Jdkoreclipse was able to get the pre-alpha ROM booting but unfortunately, not much else is working.
With the source code not being released by Google, not even the touchscreen is functional. If there is any progression on solving all the kinks we will let you know.
[RootzWiki via AndroidForums]