Update 1/7/2006: This architecture, while generally OK, is now superseded by my book. There are some critical differences.
I'm happy to finally post this document I have been working on for the past 2 months:
It's a lengthy (40 pages) analysis of ITSM and related IT governance concepts from a data architecture perspective. Included is a high level entity-relationship model, definitions, discussions of general data issues as pertinent to internal IT enablement, and some initial thoughts on data/process matrixing. Extensive coverage of the Configuration Item concept.
I hope that this is useful to ITSM practitioners!
PS. Thanks to Ben Berger of Unicorn for solving my PDF problems (and many others as well). If you want to make comments on the document send me an email and I'll send the Word document.