Corrider Systems demonstrates 256 Mbps over medium-voltage powerlines: The ultimate vision is to use powerlines to carry data near end users, then deliver the data over the final mile with Wi-Fi. This system was deployed as a test by Pacific Gas and Electric over a section of its grid. Product availability will be second quarter next year—is it too soon to dream about the potential for real broadband connectivity competition??
It will be interesting to see if this approach really works. They say they are using microwave frequencies, but not specifically what frequency. Considering that 802.11 is also using part of a "microwave frequency" range, this may not be any better than other systems being tested. Most BPL systems use a RF frequency range that disrupts long distance shortwave communications making it illegal for use in the US. In communities where the lower frequency BPL has been tested almost all shortwave reception and Amateur Radio communications have been severely compromised. As for why this is a problem, most govermental entities specifically plan on Amateur Radio operators for communications in disasters and emergencies for both short range and long range communication capabilities.
I'm a novice both in the WiFi and (even more so) amateur radio area, and I too have noticed extreme concern in the amateur radio magazines about this technology. I wonder if they'll have the clout to do anything about it, though.