If you got the free ebook "Programming Windows 8 Apps with HTML, CSS, and JavaScript" from http://www.ozbargain.com.au/node/83384, you can take this free Microsoft exam to certify your skills.
They also offer a free online HTML5 course, to help prepare you for this exam.
Nice. Might not ever use it, but why not, it's free and will come in handy I'm sure. I'm forever trying to write HTML5 webpages