have you ever heard of Photosynth? (Read about Photosynth here). From the first I heard about Photosynth, I think it would be very amazing if Photosynth can be integrated into Virtual Earth. And finally, yesterday Microsoft announced that they already do that.
This are some videos I found across the Internet about the application of Photosynth in Virtual Earth.
I think this is very great. Maybe someday it can be as good or maybe better than Google's Street View. Because it is uploaded by the people for the people, so it can grow much faster than Street View.