Download the first Web Standards Update for Visual Studio, which gives better support for HTML5, adds CSS3 and brings more new API’s to the JavaScript intellisense!  This update provides you with intellisense and validation for HTML features:

- Video and related tags

- Audio and related tag

- New input types like e-mail, url, date, and more

- Drag and drop support

- Accessibility standard WAI-ARIA

- Microdata

-Schema.org and more SEO friendly

For more information about this update, make sure to check out this blog!