Being the further adventures of: html5 already works somewhat. Article comments didn’t get the treament, last time, because they’re produced by wp_list_comments() in the comment.php template. But actually this isn’t that hard to sort, and I also took a look at the form fields in the comment post section of the page.
HTML5 is no radical departure from it’s predecessors. It offers aids to better semantic markup and embedded content, useful form validation, and a little less depreciated cruft. Most importantly it provides the platform for CSS3, about which more in a later article. But the best thing about html5 is that you can have it now, without sacrificing browser compatibility. Take a look over here where I’ve recoded Ponderwell’s site in html5. That was an afternoon’s work, and the result was sufficiently encouraging that I think I’ll be using html5 exclusively from now on. It works just fine even in IE6 – or rather, it works as well as any site ever does in that horrible browser.