Bing is currently testing a HTML5 Web app, and we can access it too. But the app is not completed, so its broken in many places, also it gives you an idea of how the app will be. Michael Gillett from MML have posted the above images showing search results and home page of new web app under testing. The app seems to be more optimized for touch, Windows 8 may be the reason behind it. Thanks to Tom Warren of Winrumors who tweeted the link to access this new web app.
You can try it here, Bing.com/bingwin.