The new version of Windows is aims at more mobile platform. Thing is they seem to be embracing the as yet unproven Windows 7 Mobile interface. The OS will potentially free Microsoft from the desktop and take on Google's Android and Mac iOS domination of the mobile computing world. Or it might get people to see that mobile can be extended to the PC and open the door to Android slates and Android PCs.
Microsoft is trying to put a positive spin on this, but it is hard to escape the conclusion that this is a move Microsoft was forced to take. They will be changing the core look and feel of their flagship product. They will be making it look more like their mobile product. And their mobile product is getting killed in the market.
The concept of a mobile Windows is cool, and Windows 8 is just more proof that Web 3.0 will be the mobile web. But Microsoft is going to play a game it has not played for a long time: second place.
(Personally we find the layout of the Windows Mobile phone too restrictive. The squares impose a certain pattern of presentation on you, all heavily branded by Microsoft. The entire joy of Androids is the fact it is a light weight OS with the apps you select arranged the way you want them arranged. We have a bad feeling about this one.)