Google Search dominates the search space and that's not going to change anytime soon. In some countries, most people don't even know there are other search engines. That's not necessarily a good thing. In the US, Google has owned about two thirds of the market for a while now.
Bing is gaining some traction and seeing some growth, but it's mostly at the expense of Yahoo, which has been powered by Bing for the past couple of years.
comScore's data shows that Google has seen very little change over the past year. Hitwise shows
some decline though. It's numbers show Google going from 68.11 percent market share in May 2011, to 65.02 percent last month. That's a 5 percent drop in market share, nothing to worry about, but still something.
Meanwhile, Bing saw a seven percent growth, from 12.29 percent market share to 13.17 percent. According to Hitwise, Yahoo is still bigger than Bing, even more surprising, it's been growing in the past 12 months, from 14.50 percent to 14.95 percent.