Microsoft says that the daily front page image that is placed on the Bing.com home page is picked by the Bing team based on the amount of "user happiness" the image can generate.
Bing.com RSS
Microsoft is apparently testing a new feature on the Bing.com front page that brings up the Bing Snapshot information box via Autosuggest when someone types in a search string.
Bing.com got a slight refresh this afternoon and is now a bit larger and appears to be finger friendly. The redesign is not massive in scope, but does alter the layout in a few areas.