However, I think as the nautilus maintainer, you’re in a unique position to experiment with new systems. Navigating your system is probably the thing that touches users the most, and can probably use the most innovating. For instance, things like beagle are ok, but I’d like more than a fancy search – I’d like to not only find my files in a myriad of ways, I’d also like easy “views” of (meta)data and “edits” of metadata (if beagle can index an id3 title, I’d like to be able to edit the id3 tag with my file manager just as easily). For that you need a lot of integration in the file manager. The file manager should be my primary interface to view and edit metadata (intrinsic metadata like id3 tags, and external metadata like the nautilus labels), the file itself (like the thumbnail, and evince, and quick editors), a collection of files as a whole (a svn/arch/git repository for instance) etc etc.

For what it’s worth, I’d support you breaking the file manager for fun and profit – projects should be allowed to fail from time to time . A lot can be learned from the failures, as long as one is willing to go back and reevaluate ones previous decisions.