I got a very prompt reply from Walter Dray, the president of Proliphix who said that they were looking at introducing these in early to mid October.

He said that the sereis is expected to run between $300 - $400. He also mentioned that there is a programming interface that runs directly over IP to talk to the UDP application in the hardware.

I originally saw the advertisement in the back of Home Automation magazine and passed the info on to Peter Rojas at Engadget.