Reports are coming that Microsoft in the near future (or from now on) will be giving Nokia and other OEMs even more control over the software they want to see running on their devices. This means that Microsoft will only do the core stuff like making an update a base firmware, and rest of the work will be handed over to OEMs. The OEMs will add their own exclusive features to bring the final firmware running on their products. After getting through the OEMs, the firmwares will also have to pass through the carriers’ testing.
So Microsoft will just do their part. This seems more like just get off from some of the work (let the OEMs do that work) than delegation of authority. Although, it would be a good news for nokia and fans as nokia are the only one who are seriously working on Windows Phone.