The latest market share data shows that Bing is well on the way to becoming a serious contender to Google.
Within the US Bing's share of search queries rose to 10.7% in August. Well behind Google's 65% share but an increase on the 9% share recorded in July.
My own experience is that Bing is growing as a source of traffic across most of my clients. Anecdotally, it looks like Yahoo is the loser.