Google has announced that the Android 4.0 source code will be released to the AOSP. The source of the previous version of Android, Honeycomb, was never made public, which caused many open source advocates to question Google’s intentions. Google’s Android compatibility chief, Dan Morrill, mentioned that the ICS code would be released “once it’s available on devices”—presumably after the release of the Galaxy Nexus.
To reiterate, these servers contain only the ‘gingerbread’ and ‘master’ branches from the old AOSP servers. We plan to release the source for the recently-announced Ice Cream Sandwich soon, once it’s available on devices.
Having full access to the Android source code will make it easier for ROM developers to roll custom builds of the OS, and will ultimately benefit the community.