I'm now a member of the HTML Working Group at the W3C, as an invited expert. I was rather surprised at how fast the membership was accepted. Surprised and faintly alarmed. I imagined existing members sitting around in the dark, rubbing their hands together and murmuring, "Ahh. Fresh meat."
I've been working with Philip in comments trying to compare RDF triples from RDFa and RDF tripes from Ian's Microdata proposal, but this type of effort deserves a more in-depth test. I still have use cases to deliver, but the ones I've uploaded to the HTML WG don't seem to be generating any discussion. Instead, I'm going to do one more document, with select use cases, hopefully ones Ian's already covered so I can compare the RDFa approach (which were typically provided with the use cases— all the use cases were provided by RDFa folks, from what I can see), and the Microdata proposal approach.
In the meantime, Ian has renamed @property to @itemprop because of the concerns we raised. This insures that there is no overlap on terminology between RDFa and Ian's Microdata proposal. There is a still a requirement, though, that the Microdata proposal be capable of generating the same RDF as RDFa, and that will be the next set of tests.
I'm open for suggestions as to the use cases to single out for testing. And I promise to be fair in my effort. After all, I'm a member of the W3C HTML WG now—I have a responsibility to be both objective and fair, in the interest of producing the best specification.