I don't know about the Nexus 10 or the GNex, but I do know that you need the binary blobs to boot the Nexus 4 from source. However you can get the factory image (which contains the blobs and doesn't require you to extract them from the device) from here: https://developers.google.com/android/nexus/images
The controversy is that there is no factory image available for the new Nexus 7, and therefore, the only way to boot a new Nexus 7 from AOSP source is to pull the blobs from the device, incurring in a legal gray area.
The controversy is that there is no factory image available for the new Nexus 7, and therefore, the only way to boot a new Nexus 7 from AOSP source is to pull the blobs from the device, incurring in a legal gray area.