breeks - 11:38 pm on Oct 16, 2013 (gmt 0)
Well I guess the beta is over :)
The asynchronous ad code is a fully asynchronous version of the AdSense ad code that offers improved web latency and a better user experience for your site’s visitors. The advantage of the asynchronous code is that it's guaranteed never to get in the way of other parts of your web page loading. This means that users will be able to load the content of your pages, even if they’re having trouble loading the ads. Mobile users in particularly will enjoy less latency when loading web pages.