What I like about your component is that you can disable the all users list and just show connections.
The only thing I don't like about CB (just the one by the way!) is that there is no "User Bulletin" type components where friends can send out information that only their connections can read. If your familiar with myspace than you'll know what I am talking about.
Since you can all ready send messages to multiple people with your plugin, I figured a send to all connections option could kind of make up for the lack of a network bulletin you follow? A reply all would be nice too.
I see what your saying though but that desicion really kind of falls in the site admins hands to enable or disable the different options.
Just my thought.. I myself think it would be cool!