HTC is apparently bringing the unannounced Shadow II UMA smartphone to T-Mobile USA.

The HTC Shadow II will be the first Windows UMA (Unlicensed Mobile Access) Microsoft Windows smartphone on the market.
T-Mobile just announced on Monday the Nokia 6301 and Samsung T339 UMA Phones.
T-Mobile customers can already choose from eight HotSpot-enabled phones, including three smartphones and a variety of Nokia and Samsung phones. The T-Mobile HotSpot @Home service offers unlimited, nationwide calling over any accessible Wi-Fi connection in addition to great in-home coverage.

Details on the HTC Shadow II phone are still sketchy. Some leaked photos float around.
The HTC UMA phone deal has been reported by Digitimes.