 <p>John Resig (jQuery) <a href="http://ejohn.org/blog/html5-doctype/" rel="nofollow noreferrer">has a say</a> in that matter. Additionally, a DocType helps make MSIE6 <a href="http://msdn.microsoft.com/en-us/library/bb250395.aspx#cssenhancements_topic2" rel="nofollow noreferrer">use the right box model</a>, and it also eases the pain of validating your site (this is a <strong>good</strong> thing for development; think of it as debugging).</p>