Re: I don't think you'll see Windows 9.
Considering Nadella's cloudy background, I think Windows will move to a 'software as a subscription' model sooner rather than later. In fact, you can deduce this from Window 8's annoying habit of nagging you to sign in with your Microsoft account.
Fortunately, for my fellow Microsoft-hating comrades, this will most definitely spell the ultimate end of Microsoft as we know it. If there's anything we detest, it is an operating system that we have to cough out money every month for and one that demands you to be online all the time. If Microsoft hadn't yet learnt from the Xbox One debacle, it is daft.