You need to add bzip2-lib and icu to the dep file.
Also mpd will not start without mpd.conf, so I'd suggest you add a start-up script to copy mpd.conf.example into /usr/local/etc as mpd.conf after first testing for it's presence.
Finally, mpd looks for alsa.conf and aliases.conf, so I guess a comment about requiring alsa-config/alsa to be installed and configured in the info file would be good