I just checked out and found interesting the new Annotea Bookmark RDF Schema (via Danny Ayers).

This: "shared bookmarks are easy to model using the same underlying architecture as Annotea annotations", where:

Annotea is a LEAD (Live Early Adoption and Demonstration) project enhancing the W3C collaboration environment with shared annotations. By annotations we mean comments, notes, explanations, or other types of external remarks that can be attached to any Web document or a selected part of the document without actually needing to touch the document. When the user gets the document he or she can also load the annotations attached to it from a selected annotation server or several servers and see what his peer group thinks.

These look like excellent candidates for schemas that will work well with / as / from iCites. And, I think the iCite net can also address the point Danny is making about it being more ideal to have a permanent identifier that doesn't need to change as data moves from one host to another.

Also of interest: Amaya, the W3C's web editor that includes Annotea and Annotea Bookmarks.