Image backup+restore probably won't work when the new tablet isn't exactly the same model as the old one. Besides, this idea should work without the help of a 3rd device.
IMHO using NFC (or display+scan a QR code) to setup a data channel should be rather trivial. Then blast the actual data across with WiFi. The heavy lifting (i.e. extract and restore state) can be done with Titanium Backup which you should use anyway.