I used a mythtv box to stream wifi tv to my zaurus. It worked like this:
One script in the mythtv box would cat /dev/video0 (that is the video source with pre-selected channel) to mencoder to get proper bitrate and resolution for zaurus and then forward the stream to a known tcp port; then, on the zaurus, I used socat to connect to the remote port and get the stream and send it to mplayer.
It works. Quality wise is not very good, but as good as the zaurus can handle.
It requires lot of processing power for my mythtv box, since on-the-fly mencoder was very cpu hungry; since I have a mini-itx box, it goes 100% load.
HTH, YMMV.