Not all websites are basically just documents with a management interface, however. Remember, there are an awful lot of sites with database back ends that stor

Not all websites are basically just documents with a management interface, however. Remember, there are an awful lot of sites with database back ends that store structured data. The technical difficulty of emitting that structured data out into a web page using a microformat (or RDFa, or whatever) is going to be pretty low, so if it's useful (for SEO or anything else), I expect it will start happening.