Craig McCaw has reportedly bought a Texas company, Clearwire, that has ITFS spectrum assets: The ITFS band is near the MMDS spectrum but was set aside primarily for educational institutions. During the last period of interest in MMDS, during the mid-1990s, some companies, including Clearwire apparently, negotiated with the educational institutions to use or buy the spectrum. The spectrum wasn't widely used by the educational organizations that controlled the spectrum.
McCaw has long been interested in fixed wireless broadband. He founded XO Communications, which owns LMDS frequencies, in the mid-1990s. XO recently joined the WiMax Forum. ALso, Nextel owns a bunch of MMDS spectrum that it bought from Worldcom.
McCaw has assembled a who's who list of execs to run the new company, being called Flux. Many of them are McCaw Cellular veterans and have held posts in other McCaw companies. Notable are Nicholas Kauser who was the CTO for AT&T Wireless and currently sits on the board of numerous Seattle companies; Rob Mechaley, who was one of the founders of RadioFrame and before that Wildfire; and Gerard Salemme, who has been involved with several McCaw companies including satellite company ICO.
McCaw is notoriously mum about new ventures so it wouldn't be surprising if we don't learn details about this one for a while. But with real WiMax products becoming available in the near future, it would certainly be fair to suppose that the company may have ambitions of rolling out a fixed broadband offering using WiMax.