We made a quick little Automator application that removes the Time Machine restrictions on what kind of disk you can back up to. We found the tip here.
We are now happily backing up or Leopard machines to the SMB Share on or DLink DNS-323.
Download the Flux Capacitor here. It is an automator action so you'll see the unix command that it runs. After you are done, Voila! You'll see ALL of your shares in Time machine - even wireless.
Obviously Apple closed this functionality for a reason so use at your own risk.
