Just curious: How do you feel about it? You didn't really say in your post.
There would be a horrid cry against it,one not heard since Obi-Won felt the disturbance in the Force when Aldaraan was blown up by the Death Star. (Yep, I went there with that analogy.) But, IF this was a direction MS was going, A one time payment with lifetime updates so long as you own your computer type thing would not offend me as much as any other scenario. And none of this pricey stuff like what you pay for Office software. Let's keep it modest.
I am a cheapskate at heart. But I can see where MS, being the small shoe-string budget Mom & Pop start-up they are may look at this as a way to replace revenue and not sell out completely to advertisers.
*Casts evil eye over shoulder at Google*