I just released Mii Transfer 0.1a to fix the launch problem on PowerPC Macs. There are no code changes, I simply linked it with a universal build of WiiRemote framework. Intel Mac users don’t need to update.
I also added a troubleshooting section to the readme file. The major problem on G4 Macs (which is actually an issue with WiiRemote framework) is pairing problems if the remote is also added in Bluetooth settings. Make sure the Wiimote is NOT connected in Bluetooth preferences (it will appear as a device named “Nintendo RVL-CNT-01”). If it does appear, disconnect and delete it. Make sure the Bluetooth setup window is CLOSED before you attempt to connect. If the connection fails, quit and relaunch.