This free application will synchronise playlists (including podcasts) on an sony ericsson phone, but it has to appear as a volume. It will even sync when the volume appears on the desktop, automatically.
Looked for MacFuse or MacFusion bluetooth, but it's not really available. Experimental at best.
However, a new cable for the W880i means that now it connects beautifully. Moved iTuneMyWalkman to Applications and ran it. Set up to have a Folder Action and a Script, and configured to use Stick 1 memory card (probably should have left the * in the settings name) and sync just Stick 1 playlist. Seems to work very well! Dragging Podcasts into the Playlist means they're transferred too.