I hope that the new (simplified) direction you are trying to take bboards won't mean that it will be isolated from other parts of the new OpenACS 4.x infrastructure such as subsites. The subsite feature is one of the major attractions of 4.x for me.
However, I guess the modular nature of the OpenACS 4.x packaging system would mean that those of us that require such features could chose our own implementation (provided, of course, that other packages do not depend on a specific implementation of the bboard system).
Finally, if other modules are not dependent on bboard, then wouldn't it be best to at least get a straight port of the AD version going now so that we have at least some bboard capability to demonstrate immediately (i.e. one in hand vs. two in the bush).
B.T.W. As always I recognize that those who actually DO THE WORK to code these things should have the final say, and I greatly appreciate the work you folks are doing.