John Chow notes the vast majority of traffic to his blog from search engines comes from Google. I see a similar pattern for this humble blog with over 95% of search engine traffic arriving from Google despite the fact that the blog has been indexed by the major players.
Although I use Firefox (where the default search engine is Google) and I hardly ever use any other search engine, I was surprised that the number of visitors from Yahoo was a paltry 2%. I also thought more people using Internet Explorer would get directed from MSN/Live as the breakdown of browsers visiting this blog is split evenly between Firefox and Internet Explorer.
As for ask.com, I mistakenly thought this search engine ceased to exist when they recently killed off the English butler Jeeves. I actually had to go and check the logs to see whether the Ask crawler had even indexed the pages.