Sold through Microsoft Store, the devices could fill in a niche for Microsoft while their OEM partners can have the carriers. This would allow Microsoft to have their own “vision” of Windows Phone and a way to update the devices directly, with no one compromising their vision. In addition, their OEMs will mostly be kept “happy” since unlocked phones are not the crux of their business model.
The other reason we raised was Microsoft maybe wanted a contingency plan—in case the Windows Phone 8 launch doesn’t go well and the currently announced devices don’t catch on. Nokia could be in trouble financially and Microsoft would need another dedicated hardware partner.
The Black Widow will strike again. Not a question of if, but when.