Jon Udell offers some insightful comments and a 14-minute screencast showing off how tagging works in Windows Vista;s Photo Gallery. His comments are remarkably insightful. I was especially struck by this one:
Conventional wisdom was that people could never be bothered to invest effort in tagging their stuff. What del.icio.us and then Flickr and then a host of other web applications showed is that people will invest that effort if the activation threshold is low and the reward is immediate. On the web, the rewards are both personal (I can more easily find my photos) and broadly social (I can interact not only with friends and family but with like-minded photographers everywhere). On the desktop, the rewards will mainly be personal and more narrowly social (friends and family), though if photos can bring their tags with them when they travel to the cloud, the broader social rewards become available too.
A few weeks ago, I called Photo Gallery one of the “killer features” in Vista. Yes, I know about iPhoto and Picasa and even Photoshop, but this is a genuinely different experience. The idea that your metadata actually lives in the file in a standard format (XMP) instead of in a separate database is groundbreaking, especially as part of a free program included with practically every new computer sold to consumers.

