Bing, Google and Yahoo have announced schema.org, where you can find markup to embed in your HTML that will help those search engines figure out whether you’re talking about a movie, a person, a recipe, etc. The markup seems quite simple. But, more important, by using it your page is more likely to be returned when someone is looking for what your page talks about.
Having the Big Three search engines dictating the metadata form is likely to be a successful move. SEO is a powerful motivator.