Whatever Happened to WiMAX?

I think the biggest issue with WiMax is the regulatory requirements, at a previous project, we wanted to use wimax to link SCADA system to the field RTUs, long story short, the regulations for that band was almost impossible to meet within the project timeframe, as it falls below the 2.4ghz, we eventually had to use a mix of 2.4/5.8ghz and VHF.