There was a recent rumor that Microsoft may be building their own Windows Phone following the announcement of the Microsoft Surface tablet. Microsoft has flatly denied this rumor today, stating that they have no interest in doing so.After looking at the design and build quality of the Microsoft Surface, I have to say I am a little disappointed. But Windows Phone is still a very new platform, and it is important that Microsoft doesn't rile up OEMs by competing with them.
We would still be very happy to see a pure Microsoft device like Google’s Nexus Series. But given Microsoft’s lack of success with their Kin devices even that sounds unlikely.
source – InformationWeek