Get the meta element out of your markup and and send the header over HTTP instead.
On Apache, add this to your root .htaccess file:
Header set X-UA-Compatible "IE=edge"
Update 10 August 2012: in response to a query, I checked again and pubdate is gone from both the WHATWG and W3C specs.
Previously, you could only mark up precise dates. So, 13 November 1905 could be expressed in HTML <time datetime="1905-11-13"> but November 1905 couldn’t be. This is a problem for historians where sometimes the precise date isn’t known.
Neither can you indicate date ranges. To mark up From “21/02/2012 to 25/02/2012″, use two separate <time> elements.
A figure can be used with or without a figcaption. However, without a caption, or an alternate means of providing an accessible name (e.g. aria-label) a figure may not provide much value in conveying its semantics alone. In some cases, it may not convey any semantics at all if its given no accessible name.
Headings in a <legend>
In forms, the <legend> element represents a caption for the form fields within a <fieldset>. Before HTML 5.2, the content of a legend had to be plain text. Now, we can include heading elements.
" elements of type number are used to let the user enter a number. They include built-in validation to reject non-numerical entries. The browser may opt to provide stepper arrows to let the user increase and decrease the value using their mouse or by simply tapping with a fingertip."