Sprint's new WiMax initiative with partner Clearwire is stalling because the high capacity wireless access points don't work very well when backhaul (the connection from the wireless radios/antennas is over old-fashioned copper phone lines.
Do the math....
If Sprint/Clearwire is promising 3-6 megabits per user over a wireless connection and the copper phone line feeding it is a T1 line (1.5 megabits), customers are going to be very disappointed. Clearwire may become a valuable customer of communities that are building out fiber networks.