Jean-Baptiste Queru, AOSP engineer for Google, has verified that GPL and LGPL portions of the Honeycomb source code have been entered into the AOSP repositories. Don't get too excited though, it's not the full source code, it's just a snapshot to be used if "incompatibilities develop over time." It still may contain code useful for developers, and something is better than nothing.
I'm a little sad that it took almost two months for Google to comply with the license they agreed to when they used GPL code, but there's little we can really do about it. If you're a Honeycomb developer, Al Sutton has worked out a set of instructions to build what has been provided -- find it at the source link. Hopefully, the community can find good use for it. [@jbqueru; Al Sutton's Blog via AndroidGuys]
Edit: Jean-Baptiste Queru gives us a correction, one that makes me happy.
Funny that nobody had noticed until now that all the GPL/LGPL Honeycomb projects were in AOSP. They were there in late January.
Sincere apologies JBQ, and thanks for restoring a little bit of faith :)