Microsoft has started showing off the Longhorn, which is supposed to be its next big thing. From what I understand it's likely to be a pretty big departure from XP. The file system looks cool enough that I want to see how it works:

At the heart of the next Windows will be a new format for storing data that Microsoft has worked on intermittently for more than a decade. Rather than each software application saving information in a different format, a new standardised file system known as WinFS will create a single, unified system.

That means users will be able to find any information on their own PCs or across their corporate networks with a single search, then collate different types of data, whether in the form of text documents, spread sheets, video or audio recordings, Microsoft executives said.

It looks rather dreadfully proprietary, which I would imagine that MS views as a feature and not a bug. If it works, this could set the Linux movement back a long, long ways. On the other hand, if it's the equivalent of WinME or worse, then it could immediately throw Linux into the ballgame.