Actually a little more complicated than what folks are saying here. Depends on the altitude of the data they are using as Bing actually has layers. In one spot that I’m personally aware of, the autogen building data is probably relatively curent. However, the ground texture it sits on is of the construction site of those buildings nearly 10 years ago. When I look at this spot in Bing Maps if I am at 250’ or above, the aerial imagery is of that 10 year old construction site. When I zoom in to 100’ the imagery changes to present day showing all of the buildings and parking lots etc.