Well, it looks like I've got a choice to make. In my last post, I mentioned that I was currently working on a new starter theme for ThemeShark.com, the base upon which all of our themes will be built for the next few months. Not a starter theme with the bulk of a complete framework, but something a little more straight forward and elegant.
I've got a list of things I'm including or, at least, want to include. First and foremost, I've got responsive , grid based design on my mind, and right now it looks like there's a good chance the Skeleton Boilerplate by Dave Gamache is going to provide an excellent foundation.
But I'm at the point where I need to decide between XHTML and HTML5. After doing some initial tests with pre- existing HTML5 Drupal themes, I was a disappointed to discover something I hadn't already been aware of: HTML5 doesn't get along well with the RDF module.