If Microsoft owned the patents they could enforce them against others. As a licensee, they simply protect themselves from Nokia enforcing it against them.
As I said elsewhere in here, a Nokia with a big stack of patents and no hardware business is going to be an ugly thing for the industry: They can go gangbusters with patent assaults while having nothing for their victim's to attack in return. All the while Microsoft will be enjoying their 10-year license.
So it smells like a very similar move to the SCO-attack on Linux. Microsoft competitors could get legally assaulted by a zombie Nokia while Microsoft itself is not associated with the legal fight.
If Microsoft owned the patents they could enforce them against others. As a licensee, they simply protect themselves from Nokia enforcing it against them.
As I said elsewhere in here, a Nokia with a big stack of patents and no hardware business is going to be an ugly thing for the industry: They can go gangbusters with patent assaults while having nothing for their victim's to attack in return. All the while Microsoft will be enjoying their 10-year license.