When I first designed this website one and half year ago, I had already implemented HTML5 navigation tags, but left them commented out because of some IE issues not parsing the unknown elements. Soon after, I found a solution, but I was too busy to bring it to work. Finally I did it today, with some extra changes, like removing all the JS from this page.
While reading the HTML5 spec, I found out about new elements that are really specific1 and it’s taking html5 in a new direction, I believe. Someday HTML5 will be as specific (or even more) than LaTeX, and we all know what it means. It could be used for more serious stuff, as long as you are able to use a couple of tags to do the essential.
If there is some kind of content that could be inside a tag (say a cite or a kbd), is it wrong if I just forget about it, and use more basic elements (div or span) to do the same? I ask this because current fast-markup languages like textile or markdown don’t support a lot of html5 features (nor you want them to). Of course you can write the tags yourself, but that would break the purpose of using such languages to ease the editing by non-tech people. The same question goes for using CKeditor and TinyMCE.
1 And still, I couldn’t find a location tag for representing geo coordinates. Disappointing, since I was expecting it to be somehow included with the geo location API.