Understanding the web to make search more relevant, Google Blog (Jan 22, 2010)
This was announced a while ago - but doesn't hurt to be reminded.
"Answer highlighting helps you get to information more quickly by seeking out and bolding the likely answer to your question right in search results. The feature is meant for searches with factual answers, such as [meet john doe director], [john lennon died], or [what was the political party of president ford]. If the pages returned for these queries contain a simple answer, the search snippet will more often include the relevant text and bold it for easy reference."
Example was empire building height - but does a good job on cost of obesity. Google.ca results are better than I recall too - snippets have dollar figures.
Posted by Gwen at March 3, 2010 08:56 PM