For this to work, it requires my tmux fork that includes what I use as the hostname in the window list.
At any rate, it'll sort my tmux sessions alphabetically by the host I'm using.
my tmux fork: https://github.com/jordansissel/tmux
Starts with:
(0) - nightfall: zsh - /home/jls/projects/tmux/trunk
(1) carrera: screen -x irc