What the heck did MS get out of this? A sales channel? They didn't get engineers (didn't most of them flee?). And they obviously didn't want the brand.
Nokia sells a ton of phones, more phones than everyone but Samsung. Most of the phones Nokia sells are basic and are sold in markets that people on HN forget still exist. The developing world is where the mobile battle is headed (Facebook and Google are making a push, even Apple has been pressured to go for the lower end market). Microsoft now has a sales channel that put handsets in 60M hands in the past 12 months. I assume they want a lot of people's first smartphone to be a Windows Mobile phone.
Patents, supply chain.
Supply chain yes, but not the patents. Microsoft receives a 10-year license to Nokia's patents, but ownership of those patents will remain with Nokia.
patents.
I don't think they even got very important ones. Nokia kept the most important ones for licensing.