According to this article, Microsoft has kicked off a research project to create software that will take over when it retires Windows.

Called Midori, the cut-down operating system is radically different to Microsoft's older programs…Not the massive install required. It is centered on the internet and does away with the dependencies that tie Windows to a single PC and is seen as Microsoft's answer to rivals' use of "virtualization" as a way to solve many of the problems of modern-day computing.

80% of Windows sales are made when a new PC is sold, so if people require less PC upgrades, Intel, and Dell will need to be looking for alternative revenue streams as well.