There are so many articles around the web (mostly on tech sites of course) with questions that what will MS do with Nokia next.
The answer to that is quite simple actually, nothing.
Even here we can see a lot of comments on people not getting the fact that MS didn't buy Nokia itself but the manufacturing plants and the rights to the name for a while. Also to the deal that Nokia can not make mobile products until 2016. That is all MS got out of the deal (Thanks to a trojan horse...)
Some people forget that Nokia is way bigger than just mobile phones. They have the most important (if not the most important but somewhere up there) patent portfolio and Im not talking about "rounded corners" patents, but patents that actually do matter. I'm a bit hungover so please do the Googling yourself for that.
Secondly, NSN (Still not renamed? Since, well, Nokia just bought the rest of the shares from Siemens) is a huge business that MS doesn't have any word in what so ever. A lot of NSN products are actually produced here and as far as I've heard the orders keep coming in.
HERE maps and other software still is Nokia's and once again MS does not own those.
A lot of people speculate if Nokia will get back into the mobile business after 2016 but no one knows that but Nokia itself. Just because they sold the fabs don't mean they can't get back. There were already talks about Nokia buying Alcatel (which has mobile plants) but I think that actually had something to do with NSN rather than mobiles. Nokia also doesn't even need a fab of their own, they can, at any time, outsource their design to someone and maybe even keep a little bit costs down with that.
So to cut it short, MS is free to do what they want with the new fabs they got but they can't do anything else to Nokia.