Microsoft appears to be very interested in the proposed "white space" auction. Basically, the white space frequencies are the wasted spectrum between the various frequency bands. Microsoft apparently wants in on ownership of these series of smaller bands to use for mobile devices.

But the FCC first has to be convinced that devices operating in the white space bands wont interfere with those in the normal bands.. So far it looks like they are not convinced: http://www.theregister.co.uk/2007/08/13/microsoft_says_white...