Hi, i don't know if they're still taking suggestions to add to the new HTML5 spec but i had what i think could be a really good idea.
A new 'context' meta tag to be used to describe the context / genre of the documents content.
The usage would be similar to that of the old 'keywords' tag but using contextual keywords such as 'news,sports,fiction,sci-fi,engineering documentation,blog' etc. etc. - The possibilities are endless, with potential for libraries of hundreds or even thousands of recognised contextual keywords to clarify the positioning and content of a document.
With search engine support it could help to make the web an easier place to both publish, categorise and search for content.
I hope to generate significant interest in this possibility and eventually get it adopted into the HTML5 spec!