New Android; Where's the 4.x Source?

Google and Samsung released the Samsung Galaxy Nexus Prime Android phone (that's a mouthful!) earlier today; this is the first public device running Android 4.0 "Ice Cream Sandwich."

The 2.x series had its source opened from the get-go, which allowed the CyanogenMod team to create optimized builds of the Android software.  But with the Android 3.0 software, the code was closed by Google until the 3.0 branch was merged back into the main code.  Basically, there were very few Android 3.0 devices because Google locked us out.  Other releases were delayed as well.

Now Android 4.0 is out and the Tech News seems pretty excited about the specs.  But I gotta ask, where is the source for Android 4.0, or even Android 3.0 now that it should be merged into the mainline?  Is there anything of value in that older 3.x code?  Perhaps Google never released it because it's poor quality, but isn't that the idea of Open Source, to be developed in the open, to air out the code so the community can squash the bugs?  It helps make everything better.

The Android 4.0 GPL parts are available here, it seems, but not yet the full source.

Has anyone had a chance to fly to Hong Kong yet to check out the new Samsung device? :)