It seems Google wants to hold on to the source code for Android Honeycomb, so that “bastardous” integrations are not made, part of the reason being that Honeycomb is optimized for a tablet UI and doesn’t fit smartphones as well.
I hope Google is not planning on providing two branches of core Android software, as that will slow down the evolution of the platform, both in terms of new features and bug fixing. Hopefully it’s rather a matter of two different UI abstractions, as a tablet desktop clearly can have more headroom than a smartphone one, despite the resolution not being that much different (at the time being).
“Personally, I believe this is less of an issue than some may make it out to be. Google will release the source code when every (sic!) it sees fit. This should please developers, and those who want some Honeycomb-goodness on their “unsupported” devices.”