Look at how a simple Google search for computer monitors has changed in the past year (below). Study it. It may not be long before all of your search results look this way.
Earlier this month, Google, Yahoo!, and Bing, simultaneously announced support for a new set of standards that can now be found at http://schema.org. The set of standards set forth are not entirely unlike http://sitemaps.org. Essentially, webmasters now have a huge wealth of HTML 5 tags that can be used with your site to enhance the ways that search engines and other spidering devices understand the content on your site.
Imagining the level of understanding that this gives the major search engines of what you do, and the new ways that you can be compared in their results, integrating these tags starts to seem like a no-brainer. No doubt that the battle of recreations in the search engine results page (spawned by Bing) is far from an end, and your SEO will no doubt be affected many more times as a result.
Perhaps to our clients here that are hosting SEO projects that have any level of seriousness, it’s time to start on that HTML 5 upgrade.