The only problem with this WSBD it can only go upto 4meg for wifi so it might not be good for wisp's. Because the future everything will be broadband heavy requiring 3+ meg download.
This is the 1st generation stuff. Carlson Wireless already has a TVWS device that will go up to 12 megs in a single channel. Start bonding multiple channels together and the speed will increase quickly, especially if the FCC allows them to use the full channel width on overlapping channels.
But again it probably take 2 years before the public like us wisp can even use the space just like how the wimax took forever to get released to wisp's. So I would say its going to be a dead technology just like how BPL was.