That's basically the same isn't it? A patent can only remain active for 20 years, assuming most of the patents are several years old the majority of them will be pretty close to expiration in 10 years time.
Note: I'm basing this on NZ patent law, but I assuming it's the same for any 1st world country...
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.
Hmm that sounds rather a lot like mafia. "Pay up or else, no matter whether we're owned by you."
Thanks for the clarification, that makes sense