Last week Google announced their asynchronous tracking for Google Analytics. This tracking is different in many ways: loads faster; code can be placed in the header rather than the bottom of the page; better uptime; and more. With the ability to place the analytics in the header the data is being recorded accurately because it is the first thing to load when someone visits the page. The previous snippet was placed at the bottom of the page; we would have to wait until the other javascripts were executed before it loaded. That meant if some other javascript was broken or someone left the page quickly, Google Analytics would not record the data.
~Lorrin