It is still early days but:

...If and when the technology is made viable, it could "create an explosion of connectivity at lower cost," said Victor Bahl, a principal researcher at Microsoft Research...
Link: WhiteFi: Broadcasting wireless Internet over TV airwaves

Not sure how sending information back across the connection is supposed to work though? Also if the frequencies used are truly unregulated isn't there going to be an increased chance of cross-device interference [just through the sheer number of devices this could encourage end users to buy/use?]