Few seem to have noticed, but the FCC has an open Notice of Inquiry in which, among other things, they say,
48. ... An alternative approach for enabling dynamic spectrum use is to extend the concepts underlying the rules for Television Band Devices to additional spectrum bands. ... Commenters should address whether they believe this concept is practical for other bands. If so, they should identify in which bands they believe such a system could work and provide details on how it would work.
This is action on Recommendation 5.13 in Section 5.6 of the FCC's National Broadband Plan. While I'm generally disappointed with the National Broadband Plan, this is one place where there's a (perhaps remote) possibility for real long term progress.
As I've commented in the past, the largest value of the TV White Spaces ruling is that it provides a path for opening up more of our incredibly under-utilized spectrum. This NOI is the first step. Comments are due by February 28, 2011 and reply comments by March 28, 2011. Directions and links are available on this Federal Register page.