I just got a bluetooth adapter and successfully installed it. My bluetooth powerbook (17") recognized the zaurus (though it too a couple tries... first it only gave me the mac address, but then I got it to actually say "zaurus" for device). It connected with the link number (1234 by default). But then it couldn't communicate with it. Tells me "device doesn't have the necessary services". I was amazed I got that far.
You just paired the devices, that's all. Outside of getting a TCP/IP connection between them, there isn't much you can do with it. Nothing user-friendly anyhow.
Unfortunately, unless Apple releases some iSync developer's documentation or Sharp gets serious about supporting syncing with OS X, I am not expecting a solution anytime soon.