ZTE N880E now runs both Android 4.1 and Windows Phone 7.5
The next HD2? And it costs about $150.
Jelly Bean Link:
http://www.engadget.com/2012/07/24/android-jelly-bean-os-manages-speedy-launch-on-ztes-n880e-smart/
Mango Link:
http://wmpoweruser.com/windows-phone-7-ported-to-the-zte-blade/