WiMAX has potential ... it just needs to present itself properly to the consumer as a viable proper choice.
I think if Verizon was behind Wimax it would be a success, i dont have faith that Sprint can do it. BTW LTE is a gsm protocol using sim cards. So any unlocked device could potential work.
I suspect that in general, WiMAX will not be 'directly' aimed at consumer use. WiMAX will be aimed at everything from PC cards to GPS to embedded devices (in cameras, cars, and just about anything you can think of). I would EXPECT LTE to offer similar services as well.. they'll be a little later on, with less hype. -- Canada = Hollywood North