(Sjoerd, I believe you mentioned this as a future plan, but I couldn't find a bug, so I'm opening this.)

Mixing together multi-user chat room tabs and private chats in the same window is a little awkward. A good solution would be to split them into two separate tabbed windows:

Multi-user chat room window:
* sort so rooms appear in a consistent order when opening favorites all at once
    * primary sort: alphabetically by server (with some clear labeling for the group, like a preceding server tab with the MOTD, like most IRC clients do)
    * secondary sort: alphabetical by room name
* default destination for all server message "chats" and multi-user chat rooms

Private chat room window:
* default destination for all private chats, including those initiated from multi-user chat servers (eg, IRC) (?)

The nice thing about this approach is that we can do things like auto-sorting chat rooms (so they show up and/or stay in consistent order). However, it then makes a somewhat arbitrary distinction or indistinction between private and multi-user messages (depending on which window private messages show up in).

Maybe we need a more creative and useful way to separate the tabs as they are now within a single window, such that there's an obvious split between multi- and single-user chats but not so much that it gets in the way?