Ok, I will have to be satisfied with two IP addresses for the device. My Edimax Wifi dongle is still working fine
Getting Bluetooth working from Ubuntu 12.10 was harder, but it now works. I had to install Blueman by sudo ap-get install blueman, as the installed Bluetooth manager does not have the required capability (or at least it doesn't look like it has). This results in a second bluetooth icon at the top right of the screen. This lets you set up the device, including pairing and connecting to the Network Access Point.
Unforunately blueman 1.23 has a bug in this functionality, so I had to apply a patch that added 4 lines to one of the python files. I did this manually.
That resulted in bnep0 being created, but it did not seem to get configured, so I did: ifconfig bnep0 10.0.0.1, and that did the trick. I can now connect via ssh. As the IP address is the same as the USB one, I can reuse the same connection in the Eclipse Remote System Explorer.
Is there are real advantage in using the Wifi dongle, now that Bluetooth networking works? Even the tiny edimax dongle gets in the way with the TRACK3R model.