You know - I think MS has to keep on pumping millions of dollars in tv ads or other streams of media to see Bing catch on. In our society - when we want to look up something, we say,"Google xyz". That is burned into our brain. Bing, I think, is for people that are more tech savy and want to experiment with the new SE. I can't see the average searcher using Bing.
If Bing catches on...it's going to take a while. Maybe in the future, instead of saying, "Google xyz" - it could be "Bing xyz".