Invited blogs instead of inboxes

As can be seen from the list of innovations , inboxes appeared on Habré - several recipients at once, indicated in the To field by commas (where, unfortunately, you will not add new people after creation), where they can all communicate in the comments.

This is of course, just wonderful, but it would be possible to add closed “by invitation” Blogs along with these / instead of these inboxes, which you can only join by the creator / moderator of the blog?

Give blogs: Habrazborki, Twitter Party, Habraelita, where you can discuss pressing issues in a familiar quiet company :)
')
PS At the moment in connection with inbox-letters there is a very annoying and unexpected bug. It seems that, apart from the message about the letter itself, all correspondence within the letter is sent to all addressees , and not just the replies to your comments, as in ordinary topics — nothing other than spam can be called .