A major problem with that spec is Apple claiming patents for touch events:

<a href="http://www.techdirt.com/articles/20111213/02292717063/apple-abuses-patent-system-again-to-obstruct-w3c-open-standard.shtml" rel="nofollow">Apple Abuses Patent System Again To Obstruct W3C Open Standard</a>
<a href="http://my.opera.com/haavard/blog/2011/12/09/apple-w3c" rel="nofollow">http://my.opera.com/haavard/blog/2011/12/09/apple-w3c</a>

Until that's resolved, the spec is basically in a holding pattern and for all intents a proprietary document since the W3C is basically in legal limbo.