The chipset used in the phone has support for all bands but unless sprint put a sim card slot in the phone and the necessary hardware for the radio to work it will be CDMA only.
It uses the Qualcomm® Snapdragon™ QSD8650 (1GHz) processor...
Special Features: Embedded 600MHz DSP (GSM, GPRS, EDGE, UMTS/WCDMA, HSDPA, HSUPA, MBMS, CDMA2000 1xRTT, CDMA2000 1xEV-DO, CDMA2000 1xEV-DO Rev. 1, CDMA2000 1xEV-DO Rev. B, baseband), Embedded Seventh-generation gpsOne GPS module, gpsOneXTRA Assistance
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http://pdadb.net/index.php?m=cpu&id=...dragon_qsd8650