I have noticed over the last year especially this one a slow rise in Bing traffic over Google. Right now Google is 56% Bing is 42% rest go to some others. I do the same PPC for both conversions are very close as well.
So with that said I have focused more on Bing because it is easier to rank an old established website (10+ years).
Several years ago a yahoo talked the owners into going to a new improved version and it was a disaster. I watched the search terms go poof and conversions down the tube.
I was asked to take it back so I reverted it back to the old website improved the images and other small things and it has been moving up since.
The interesting part is the traffic. Upper income bracket, middle age, male, should have been in college during the Google revolution.
I wonder are the old Googlers moving away?