Apparently Craig McCaw has formed a new company, Flux, and has acquired some MMDS spectrum: Little else is known about what plans the company might have.
Glenn thinks McCaw could use the spectrum to circumvent Wi-Fi and sell backhaul and business services. I think that any technology deployed over the MMDS spectrum will end up being a residential or a small to medium business offering--something that competes with DSL or offers a similar service where DSL or other broadband options aren't available.
Meanwhile, Nextel has snapped up a bunch of MMDS spectrum and McCaw just resigned from Nextel's board. I've heard that Nextel may want to use the spectrum to deploy a mobile WiMAX service which would essentially offer 3G services. We may learn more at the end of January when a Nextel exec will be one of the keynote speakers at the Wireless Communications Association annual meeting. That conference was the place to be when MMDS and LMDS were hot.