Although the phone supposedly looks like the HTC One (M8), down to the inclusion of the Duo Camera and BoomSound speakers, this rumor said that the phone is based on an unannounced model called the A9. The latter model is expected to offer high-end specs at a mid-range price.
A report published on Sunday cites a tweet from WinRumors founder Tom Warren, as revealing that a Windows Phone 8.1 version of the HTC One (M8) is indeed coming. Whether we will see the same specs, is unknown. What we do know, is that if the GDR1 update comes out in time, the Dot View case used on the HTC One (M8) could be offered for the HTC One (W8) as well.
source: @TomWarren via WMPoweruser