LTE will be for WiMAX what GSM has been for CDMA. It is all a matter of customer acquisition costs and the cost of equipment to enable WiMAX operators to compete on equal terms with UMTS/HSPA. This does not imply total abandonment of the technology, just that it has evolved from being considered as the primary access in remote zones (a market that WiMAX has been trying to champion) and into a niche technology and not achieving the economies of scale to lower the cost of deploying it.
Another important factor has been the decision by Alcatel-Lucent and Nokia Siemens Networks to concentrate their efforts on the development of LTE as the technology for 4G, following the lead of Ericsson and Qualcomm. These two vendors have had a very good level of success with WiMAX and so this has a huge impact on the possibility of WiMAX achieving economies of scale similar to those of LTE. The announcements by these manufacturers have relegated WiMAX to a niche technology position in the market.
It can already be seen that the test equipment and optimisation vendors are also following the money; toward LTE. The fact that niche WiMAX deployments that comprise of both fixed and mobile deployments means that it reduces the imperitive to test. Test equipment vendors are said to be "dabbling" in WiMAX, but see LTE as the real area to focus on. Optimisation in this case also becomes less important and niche operators deploying WiMAX cannot afford to spend vast amount of money on optimisation anyway. This may in turn lead to a poorer quality of service for customers, making it even more difficult for WiMAX to compete.