You may have heard of Microsoft “Blue” or “Windows Blue”. I will not give you any inside information (as I simply do not have it), but here I found a good definition of what Blue is
“Blue, according to these guys, is not the code name for a new version of Windows. Rather, it is a process of incremental updates which users will get automatically.”
I would recommend you read the entire blog post by Tim Anderson. It is short, but to the point about the future of PCs, Windows 8, and tablets.