Hackers rejoice! Google has made available the source code for Android 4.0 to developers. This means that "ROM cookers" can now begin hacking the source code onto their older devices that didn't officially get the delicious Ice Cream Sandwich bits.
A post over on Google Groups detailed the release, saying that "this is actually the source code for version 4.0.1 of Android, which is the specific version that will ship on the Galaxy Nexus, the first Android 4.0 device." Notably the post points out that various Honeycomb source is also available with this release, however "since Honeycomb was a little incomplete, [Google] wants everyone to focus on Ice Cream Sandwich."
The code includes build configurations for the Galaxy Nexus, which will build the default system image for the device, and the team says this will be coming for more devices later.
Details on downloading the code is available here, however it may not be complete yet as the team is still uploading all the code. Its great to see Google being so proactive with this version of Android. Happy hacking!