I'd work with your local sales team for the full details, but my understanding......
Until they products merge.....
If you want to buy ClearPass Guest (Amigopod) today, you'll be provided the upgrade path to ClearPass Policy Manager and ClearPass Guest on the converged platform. So what does this mean.....
If you buy the hardware version, definitely check with your local team on the options for the upgrade. I've heard that you will be able to backup Amigopod; wipe the appliance and load Policy Manager; and restore Amigopod. I've also heard there may be options for an "RMA" type scenario where you'll get a new appliance with Policy Manager; then restore Amigopod to it and return the older hardware. In either scenario, there may be some manual reconfigurations to match up some Amigopod functionality to Policy Manager that TAC or a partner could help with.