I used Kies to upgrade from the first AT&T ICS release to this second AT&T ICS release. Indeed, the keyboard backlight problem is gone without any hacks. Seems like the fast dormancy related kernel wakelock that was sucking up the battery life by keeping the phone awake is also gone.
For some reason the update wouldn't download OTA. Software update always claimed by software was up to date.
As far as I can tell, this ICS update is solid.
Nothing else to report, so far.