On the left is the HTC One M8 running android, and on the right is the same hardware but running Windows Phone. It is exactly the same 5-inch 1080p aluminium unibody design, with just the Windows Phone logo on the back. It comes with on-screen buttons, built-in infrared, the same Snapdragon 801 processor and Duo Camera and 4mp ultrapixel. In fact it is identical except for the operating system. Only one catch, it is only available in the USA and with Verizon and AT&T at the moment.

Updated. Thanks to Richard Yates for the additional information.