Nice brush, thanks for the upload! Hope you don't mind that I add it to this still expanding list of SyntaxHighlighter brushes http://www.undermyhat.org/blog/2009/09/list-of-brushes-syntaxhighligher/ (with full credit of course, and I'd be happy to add a link to an information page on the YAML brush)
Thanks Abel for this excellent post. If you wish to link to a post on my personnal blog annoucing the availability of this brush, feel free to put a reference to this link :)