as the demand on the finite spectrum increases these 'white spaces' (however it is defined or found) will be used. there is a lot of research going on concerning using these 'white spaces' and WILL continue and increase as time moves forward.
It WILL continue, but that doesn't mean that it ultimately WILL happen.
Unless, of course, you're from the future, and connecting to our dimension via white space. -- The goal of the broadcast engineer is to get all the meters on the transmitter to go as far to the right as possible!!