In case you haven’t heard, WinFS is the new relational file system for Windows. Read the blurb on the official page, I’m not going to repeat that here. Now, is that a good thing?
Reading the SDK docs for the current beta 1 refresh, one might think the authors are mainly promoting the use of more relational database technology (and spreading false information such as that the SQL keyword used to select relationally linked data is UNION), but obviously WinFS is a lot more than that, with its sophisticated system integration, schematised storage of arbitrary information, search, sharing and synchronisation facilities. So yes, I think it’s a good thing, generally.
The one thing that’s going to decide if WinFS is going to fly or not, is whether mainstream applications will include support for it. It will be available for Windows XP as well as Vista, so operating system support shouldn’t be too great a problem (I hope, there are always astonishingly many people who don’t even use the second-latest Windows version yet), but application support is much more important than that. Obviously, Outlook 12 will support it out of the box. It will, right?