Very cool - this is pretty similar to microformats.org's design principles. I could see this kind of HTML markup used as an alternative to maintaining a separate REST based API.
But less ambitious: it's actually not a bad way (I think - I don't know enough about JQuery to have an idea about the performance of this) to do client side filtering of data presented in tables. His technique, at least, is more readable than the kludges I've come up with to do that.
In any case, this is fairly cool indeed.