I am using wince now (mobile 6.5). Samsung Omnia II. Works alright, but for MS to compete with Iphone 4 right now may not be the best decision. Maybe it is best to wait for the Tsunami to pass. What does the HTC WiMAX phone run? Never mind, Android.
Omnia II is on Verizon, ARM 780 processor, very slow Internet, even on "3G". Runs about .7 Mbs, a lot of times it runs on "1G".... .14 Mbs (my US Robotics modem was faster. :) )