The OEMS are in a tough place. They have to compete with actual HW innovation ( apple ) on one side, and with subsidized hardware on the other side ( amazon ). And if they succeed, all the margins go to Microsoft.
At least, in the case of Android, they can add value, or extra revenue streams. In the case of linux, the open nature, would provide a competitive edge.
Why would any OEM be interested in selling win8 devices? If microsoft is going the way of the console ( like apple and amazon are doing ), shouldnt microsoft be paying them instead of the other way around?