Sprint needs the smart phone to promote its WiMax technology
Carrier faces tough battle ahead against AT&T, Verizon's planned use of rival LTE
Previously called the Supersonic, it will be released this summer
E-commerce payment system lets users charge $25 a month to Verizon Wireless accounts
Says it will be only U.S. carrier to offer phones with all the major OSes
Release is prior to close of Cisco's acquisition of high-definition systems
Includes information on proposed wireless network for emergency responders
Few differences beyond Verizon's plan to come to market faster; both downplay WiMax
WiMax phone to have 4.3-inch display, Android 2.1 with Sense UI (see video, below)
Sprint is mum on whether its Google smartphone will carry full $529 price tag
