That's true, but my thought here is that if something like Rails automatically generated semantic web structure when it serves the pages then as people build we

That's true, but my thought here is that if something like Rails automatically generated semantic web structure when it serves the pages then as people build web apps we get the semantic stuff for free. Think if Scribd had something like that when they built their site. Then all of those documents could have extra data, pulled from the database and the document itself, embedded in the page. I guess what I'm thinking of is an extension to something like ActiveRecord that pulls that information out of your models and database to embed in your pages.