Today as I opened Bing, as usual provided with a stunning Home page and today was the video HomePage ! A time-lapse of a thunderstorm. But there was something more, Apart from its regular ‘Previous, Next, Info’ buttons, there was another to close & expand the Taskbar.
And it closes the Taskbar at the bottom of HomePage,
Check if you are getting this update- http://www.bing.com/ (Change your location to US from top of Bing Homepage)