you realize that the semantic web is not about the semantics of the data, but instead about the semantics of the schema, right?
I'm having trouble getting your point here. A schema can be thought of as metadata about the data to which it is applied; so "semantics of the schema" are also implicitly "semantics of the data" in a sense. I guess I'm missing some nuance about the point you're trying to make... would you care to elaborate?
I'd give good odds that joshu already knows this, but I'd like to point out that a lot of work has gone into making freebase's schema machine readable. The schema is stored and constructed in the same way as all other data in freebase (as are metaschema, such as http://www.freebase.com/view/type/object/type and so on).
you realize that the semantic web is not about the semantics of the data, but instead about the semantics of the schema, right?
The meaning of semantics (semantics of semantics?) can get philosophical real quick. Here I'm just rolling with the OP's notion of things, not strings.