Windows 7 will be the last good "desktop OS" from Microsoft. They're going to completely kill the desktop mode in future versions, slowly but surely. They will turn it into DOS, where the desktop is but a fading "app", and will bury it deep inside the Metro mode. I'm almost certain they will do this.

There are rumors that with Windows 10 and beyond they will also try to turn Windows's license model into a subscription model, which will completely kill Windows for just about any "regular consumer", and will turn it into a mostly enterprise OS, because only the enterprise customers will (probably) agree to that kind of model.

Consumers already believe Windows is "free" with their laptop purchase, and that they don't have to pay anything else after that. A subscription model will be a huge turn off for consumers, not matter how little it costs (even $1 per month).

We can only hope that before Windows 7 gets too long in the tooth, Ubuntu or some other multi-OEM OS (Android? Chrome OS?) will become popular enough in the mainstream, and mature enough, to make it a viable alternative five years down the road (I think they will be).