Omg... They are lying out their ass saying that 10 will be the "last" major update. My lord the lies.
Nah, they're just going for a more "agile" model like Firefox and Chrome have been doing, or maybe more like OS X. I love how people are calling this "radical" when Apple's been doing it for, what, 15 years??
Sorry I thought I clarified once, but I'll do it again. I found it radical and ambitious to announce that they would be in effect branding their OS as "Windows 10"
forever, by denying there would ever be any new major releases. It's not even something that Apple did.
Now Apple can move on, merge their iOS and OS X, create a new brand, and make Microsoft look like idiots again playing catch up with egg on their face. Or not. Doesn't matter. Microsoft has still locked themselves into a strategy.
edit - I never asserted that the technology was either radical or ambitious. It's radical and ambitious by comparison with their established business practices, especially coming off the debacle of their previous major release. It's an unnecessary risk to the Windows brand to make such an announcement.