Some unofficial builds have been floating around for a while, but tonight, it looks like Nexus S 4G owners are about to get some allegedly official ICS update action. Over on the XDA forums, user mrxkills has uploaded all the files necessary to get your Sprint Google Experience device updated to 4.0.4.
You read that right: 4.0.4. Compared to 4.0.3, the build we've seen passed around for a while on other devices like the Xoom and the Galaxy Nexus. This is also build number IMM26, compared to IML74K. Unfortunately, we don't know what of all changed yet, outside of the presence of WiMax drivers in this build.
I flashed all of the files via fastboot, and everything is working fine. Kinda nice to see something "official" for ns4g
The poster on XDA has said he plans on leaving the files available for download for about three days, so if you're looking to get the jump on Sprint's official release, hit up the thread sooner rather than later. However, if you're reading this in the future, or in the event Dropbox cuts off downloads due to overuse, we've got some mirrors for you right here:
Note: For reasons unknown, Minus in mirror 2 is renaming .exe extensions to .bin, so be sure to correct this after downloading before proceeding.
Happy flashing, but remember to be careful - neither XDA nor Android Police will be responsible for any potential harm to your device.
Update: Installation video by qbking77:
Source: XDA, thanks Justin!