There could be some shareholder influence into this all. On Dell's part I heard M. Dell aims to get rid off shareholder's pressure for stable quarterly results in order to restructure Dell, and therefore the buyout.
And then I guess Steve "Chair" Ballmer heard that "look at Apple!" too often. They took some inspiration from Cuppertino already and while it was mostly desktop features in the past they now try to copy business model features like controlling both hardware and software.
It's not just mice any more, Nokia, Surface, Dell. Looking at the margin Apple manages to cash in and with the pc market developing limits to the perspective of endless expansion MS might hope to U-turn the course and try to become an Apple 2.0.
Will it work? I doubt it, there is a chance they fail to reach Pure Apple status and end as apple puree instead.
Licensing OSX for Apple hardware only has been a cornerstone of Apple's strategy, will we see a MS replica of this?
Remember what they did to fight DrDos, will MS have the upright, straight character to withstand the temptations to tweak win(n+1) just a little bit to make it run just a tad faster on MS hardware? Will you believe them when they put an honest face on saying "nooo, we didn't and we wouldn't, ever..."?
MS as a producer of "standard" OS and software grew up together with that multitude of hardware makers that developed "standard" hardware, with both sides defining standard on each other.
Then Linux grew up and it now runs on everything that knows how to 01 + 01 = 10. A different approach to becoming standard and it succeeded, there is no windows for wristwatches, no windows for routers, etc. The pc "standard" is on it's way into marginality. Less important to defend that stronghold.
I see it as an motion of retreat when MS now tries to follow Apple, producing harware and OS/software. It will (further) alienate established hardware producers and it will open up fields fpr Linux on the desktop.