Being the best search engine Google gives much better and latest result. But if somehow end up with browser that has Bing toolbar and Bing as a default search engine I don't mind diving in. I experience that Bing also provides relatively satisfactory result.
But if you ask for so search something in blank browser I'll go for Google. I'm just use to it and I think many people use to it. It's habbit that cannot be changed so easily.