Adding to and to some extent, firming up the rumors, it looks like in much the same way Microsoft has decided to manufacturer its' own branded tablet, there are evidently plans to do something similar with respect to a Windows Phone 8 device.
Not particularly surprising as there seems to be a general "if you want something done right" attitude at Microsoft, which I hope if nothing else, will drive partners and other vendors, to up their game.
SOURCE: Microsoft Surface Phone release date: Windows Phone 8, 2013 launch