Client 4.4.5 released.
Audio system added:
The client now supports background music and sound effects!
It doesn't ship with any audio files except for paging beep (for systems on which paging otherwise wouldn't work) though.
You can download a sound and music addon pack here, and extract them to TomeNET/lib/xtra/ folder, so that you end up with a ../xtra/sound and a ../xtra/music folder, containing the audio substructure:
sound pack (~3MB):
http://www.mediafire.com/?l0jz5vz0kdwmusic pack (~104MB):
http://www.mediafire.com/?hywz2im1mhmNote: Audio options were added in '=' menu, and you can hit CTRL+U to invoke a mixer screen, as well as CTRL+C to toggle music and CTRL+N to toggle all audio.
Other new features:
Options cleaned up.
.tomenetrc (in user's home folder) has been improved and is now read+written (Linux clients)
tomenet.ini improved and cleaned up (Windows clients)
Added T key for quick'n'dirty macros which allows easy mimicry macros, eg just T191 to polymorph into a grizzly bear

Internal timer on Windows machines has been improved, or rather, a workaround for Windows' sucky default timer has been implemented, allowing weather effects to go much smoother now.
Char names can now also be specified on the command-line, allowing complete auto-login.
Guide has been improved a lot.
If you don't want to overwrite your tomenet.ini file with the new version, edit your tomenet.ini in a text editor, and rename "[Angband]" to "[Base]" and "[MAngband]" to "[Online]", or you will be showered with errors when you try to run the client.

Also, if you don't use the new lib/user/options.prf, most audio options will be disabled; after you logged in you can just press = 2 (User Interface Options 2) and enable them manually. Don't forget to save them afterwards.