Today Chris Coyier well known for his public talks about pseudo selectors in CSS3 has brought us a video explaining his thoughts on how to write very lightweight markup using HTML5, the topic is very heated and a lot of debate still rages on about the correct ways to write semantic HTML5 markup but at the end we all achieve the result we seek.
In the video Chris dives into his true thoughts about what he believes makes great and lightweight semantic markup by taking a PSD and picturing it as plain text code in an HTML file, without further a due click the below link and hope you enjoy the video as much as i did.
http://css-tricks.com/video-screencasts/100-lets-write-semantic-markup/