If Malte and his groups are going to play a (or "the"?) significant coordination role, it would make sense for them to host the tree(s) (and he's going to do that in the short term, at least, anyway).
So while hosting it on the openacs.org server is certainly possible, letting Malte do the hosting might make more sense. We could alway link to his server - "looking for the Good Old Days? You can find them over here!".
The permissions model's is going to be an issue in OpenACS 4, too ... not that I want this thread to diverge but I keep worrying about its scalability ...
