Does Google own the copyright to contributed code? I assume the Android project contains patches from outside developers and they don't require copyright to be assigned to Google.
I guess in my hypothetical scenario, they could relicense them as GPL but then they'd have redistribution requirements via GPL virality - at least for those bits.
Or they'd need to restructure their parts of the project around them to avoid the viral aspect, like they have for the Linux kernel.
I guess my point is more that not every part of every Free Software project is always released to the public under that license. "Android 3.0 is not Free Software yet, but will be" is not that different to other common OSS project scenarios.
To be completely 110% "open" you'd GPL (or even AGPL) and not ask for assignment, which would level the playing field for everyone. But it's not common for business sponsored projects, or required to be Free Software. And again, even RMS accepts that there are strategic reasons to use non-copyleft licences for e.g. audio and video codecs as widespread adoption of proprietary alternatives would harm Free Software.
Even if AOSP (Android Open Source Project) was GPL licensed, Google owns the copyright. Which means they can still make early releases to vendors (like Motorola for the Xoom) under a different license, and then make the public AOSP release under an OSS license later.
This is no different from Trolltech's former model with Qt, or the dozens of other free software libraries where the developer makes some extra money from non-GPL Licensing on the side.
The point is that Android 2.3 is Free Software, even if Android 3.0 is not Free Software yet. Google can't do anything to take back 2.3 now, it has freed it.
<Speculation> I'd be very surprised if Motorola got Android 3.0 for the Xoom under any OSS license. I imagine it would have been given to them under a special proprietary NDA-equipped license, or maybe even only licensed as a binary. </Speculation>