updated 04:00 pm EST, Tue December 20, 2011
Google Nexus S and Galaxy Nexus hit by battery bug
Google's Android 4.0 update for the Nexus S stalled out Tuesday. The company posted on its forums that it was holding the update to "monitor feedback" after users reported unusually high battery drain. Possibly triggered by a processor use spike, the problem wasn't enough to stop updates worldwide, but the upgrade wouldn't return until Google was satisfied there wasn't an issue.
The issue may be systemic to a recent update to Android 4.0. Galaxy Nexus owners have mentioned elsewhere on the Google forums that they've seen similar battery drain issues. In their cases, it may be that the kernel driving the low level of the software is artificially keeping the device awake even if the screen is off, sapping battery far faster than it would otherwise.
Google hasn't formally acknowledged the Galaxy Nexus issue, although it hasn't pushed the 4.0.3 update to those devices. As stock Android hardware, either won't need to wait to get fixes once made public.