While nobody doubts mobile WiMax's momentum, many are expressing strong doubts.

"It has to overcome a whole lot of hurdles that [proponents] are saying are insignificant," said Derek Kerton, principal of the Kerton Group, a telecom consulting firm. "They have to match rhetoric to reality."

Enormous stakes

The advent of mobile WiMax is far more than just a matter of introducing new technology. It has the potential to significantly alter the pecking order in the cellular industry. And, more important, it has the potential to change what people do while they're mobile.

Of the four nationwide cellular carriers in the U.S., only Sprint has enough spectrum to create a nationwide WiMax network. If its claims for mobile WiMax bear out, "it's very possible it will hurt the others' 3G service," Locke said. That's important to the competitive landscape because Sprint has been staggering recently while AT&T/Cingular and Verizon Wireless, the two largest U.S. cellular operators, have been awash in profits and rapidly gaining new subscribers.