supposed to be a space for logged-in user to discuss things in private. (not this, exactly; this is a blogpost about that space i'm talking about.)
group discussions are working now. once a group has been created, it can be selected as "audience" for a blog post, new or existing ones. if the group has been set to protected, only group members can see posts or comments. if it's not protected, then anybody can see them.
for now, anybody with a user account here can publish blog posts and assign them to any existing group. also for now, even if s/he is not a member of that group. (this can be fixed with some tricky SQL queries, but as long as there are no real users, it can wait.)
anybody can comment on posts they can see, but unless they have a user account, their comments will wait in a moderation queue before they become visible.