This is just a wild guess, but when I was checking for coverage in my area today, because I was looking into data cards. Last time I checked the entire area was covered, and I simply was checking for any dead spots.
Well too my surprise all of the downtown area is showing up with future tower icons all over the map. One of these towers is just half a mile away from where I live. The entire area is covered for EV-DO Rev.A for a while.
So I am just assuming that those towers will be upgraded too WiMAX and be up and running in the next 90 days. Double check your coverage areas and see if you are getting the same results.
It may or may not be a glitch, it could be a part of their synergy sites with the Nextel cell sites. It could mean they're going to be adding CDMA panels to Nextel sites at those locations. They've been doing a lot of that all over in the past year. If I pull up Chicago, there's future towers all over the suburbs.
Its hard to say whether or not those will have XOHM/WiMAX on them or not.