Filesystems, Metadata and Future OS Integration?

wdebruij asks: "After reading the 'The Mac, Metadata, and the World' article posted a few days earlier I was wondering what metadata progress is made outside of the Mac platform. I'm currently programming a set-based metadata system working on top of the standard file-system (called AtomsNet) and would like to know how the Slashdot community sees the future of metadata support in operating systems. The Resource Description Format and MPEG7 look like promising initiatives, but I do not know of any real life implementations so far."