"The Android 2.3 code is being posted in the Android Open Source
Project (AOSP) repositories. It would have been nice to see it
while it was under development, but this is far better than
nothing. "Even though Nexus S is designed to be suitable for AOSP
work, there are some caveats. I very strongly recommend against
trying to use Nexus S for anything related to AOSP at the moment.
Trying to unlock or use your Nexus S for AOSP work could easily
turn it into a Nexus B (where B means 'brick'); I have two of
those, they're not very useful."