Adding new spectrum is a stop-gap measure at best. Double the amount of spectrum and you've only bought a few years of capacity growth. Then what? Long-term wireless broadband growth can only be accommodated through femtocellular architectures which allow greater frequency reuse -- the implication being that we will eventually need access points or base stations on every home and business.
If we don't have net-neutrality and other regulations on the wired broadband infrastructure, then wireless too will become non-competitive as companies such as Verizon and Comcast will completely control access to the only wired infrastructure capable of supporting future wireless networks.
In the end it may well be that the only feasible solution is that broadband access, both wired and wireless, be treated as utilities. Can we really have multiple wireless networks deployed with base stations every few meters? Even if spectrum were available, how would a new wireless service provider enter the market? To ensure coverage, how would they entice every home owner to install (and power) a device from a company that they may not want to do business with? How can they compete with the wired service provider who can simply include radios in the fiber or cable termination equipment? In short, they can't. And, if we don't have competitive (or at least equal) access, then we also can't have competitive and innovative services.