Today the W3C released an official HTML5 logo. Its a call to rally forward the advancement of the HTML5 spec.
Just as quickly, the awesome designer Jen Simmons branded the HTML5 Logo for Drupal.
Those are the shiny new logo's you see on top.
I'm using the Sky Theme, which uses HTML5 and CSS3. It still gives you some ugly code, but it is more or less HTML5 compliant. I've made some modifications here and there, mostly to the CSS, but I want to do a complete rewrite that gives pure HTML5. I'll be working on that shortly. After all this is the future!
Btw, both these logo's are licensed Creative Commons Attribution 3.0