HSPA+ and LTE aren't relevant to "what should Nokia have released as a WWAN tablet". Those would be just as ill-advised, 18 months ago, as WiMAX.

Don't compare WiMAX to HSPA+ nor LTE for this discussion. That's pointless. Comparing one half-baked platform to two other half-baked platforms is ... quarter-baked logic. :-)

Compare WiMAX coverage and maturity to GPRS/EDGE/HSDPA/HSUPA and/or 1xRTT/EVDOrev0/EVDOrevA, as of 18 months ago, 12 months ago, 6 months ago, and today. Are you still telling me WiMAX was the right tablet choice for Nokia to have announced and delivered within the last 18 months?