interesting...
I´ve asked this questíon at Nokia Developer website as well, this is the answer from a Nokia dev:
"If you get (from the manufacturer or otherwise) or manage to reverse engineer the interfaces/protocols that such equipment use, then there's no reason why you couldn't write an app that can control them from your N9.

A good way to start with such reverse-engineering is to configure a phone for which such an app exists to use only WLAN, and then to force the WLAN traffic to go through a proxy server that you control (i.e. runs on your PC). Then at the proxy you can monitor the traffic between the phone/app and whatever box is is talking to and being to figure out the protocol."