IE9 Platform Preview 3

Back in March at Mix10, Dean Hachamovitch, the General Manager of the Internet Explorer team, introduced the IE9 Platform Preview, an early look at the features coming to Internet Explorer 9 (including a new JavaScript engine, HTML 5 support, GPU acceleration, and more).  It’s not a beta per-se; the browser doesn’t provide a complete experience – there’s no address bar or back button, for