Device diversity can be a good and bad thing for an operating system because some consumers like choice and some get confused or overwhelmed. Microsoft has been trying to strike a balance between iOS and Android where they provide choice, but not too much crazy variation. Recently Japanese company Mouse Computer has announced plans to make Window Phone handsets. Little is know about specs, but the device will support LTE and sold off contract.
Microsoft has always wanted a rich ecosystem of different device OEMs and unique hardware, but Nokia devices have continued to dominate the Windows Phone device market. With new partners Microsoft hopes to break into different markets and offer devices running Windows Phone which consumers already trust and recognize. A good example of Microsoft taking advantage of good design is with the HTC One M8 for Windows which has the exact same hardware as the Android variant.