general metacontact issues
Though I've found no bugs with it so far, I feel I should point out some things that should be done.
When you "remove from roster" on a metacontact it should really warn you that you're about to delete multiple contacts, if that is the actual behavior. I haven't determined what really happens when you do that.
Also useful might be the ability to have the metacontacts sorted by status, so that if there's a Jabber one set to DND, an AIM one set to Away, and a Yahoo one set to Available, the Yahoo one should be shown, and double clicking should message that one.
And just to be picky, when I expand them it's hard to tell they're expanded. Perhaps indenting them a little more visibly would be useful.