Why not just use plain old acs-subsite?
I think it makes more sense to use OpenACS built in features rather then the full blown .LRN system that contains many applicaton specific items we don't need. Eventually we want to move the general community features into subsite. We already have a .LRN subsite setup here, but noone uses or maintains it.
So I guess my opinion is, we don't really need it, the community it not really that busy.
If it was decided to do it, we should use subsites, not .LRN. And we would need a way to get a full view of all projects as well.