What struck me about this was the emphasis on the business market. Even though Nadella denies that they'll be focusing more on business than consumer, every time the interviewer tries to ask about consumer products, Nadella immediately starts talking about dual-use products, how important he thinks it is for MS devices to be usable for work too. It looks like, if you just want something for your home and aren't interested in bringing it to work, Microsoft doesn't want to know you.
This doesn't explain why they are slowly killing WPF. It's perfect for business applications.