There are a fair number of people doing it. The big names all seem to be in the northwest though. Look up Steve Weast's stuff. He seems to be the man when it comes to coldwater.
I have a local tank that has been running for maybe five or six months now, but I still wouldn't trust it with a real bioload. The cold slows everything's growth by a shocking amount, and I still wouldn't say that the tank is 'cycled'. Once this portion is online and healthy, I plan on expanding the system with a couple isolated displays plumbed in and housing some fish. I need a sarcastic fringehead pretty badly.