This is a minimal list - I haven't searched through the code thoroughly.

* Add a muster display to the main window, showing how many of each piece
  has been taken.

* Remove the server functionality to a new program, so that two remote
  players can play on the the machine.

* Get XCreatePixmapCursor working with the piece pixmaps.

* Play more interesting sounds than "beep", and allow them to be
  varied.

* Get a proper move-generation routine!
