Airshows can be deadly to pilots, but up until this tragedy, safe for spectators: "John Cudahy, the president of the International Council of Air Shows, said Friday that no spectators have died at any air show in the country since 1952."
The last 2 years I went to Osh Kosh (2006 and 2008) there were two fatalities - one when a visiting pilot crashed on his way in (a lot of people fly in and camp at the air show) and another when two reno air race plans doing a race demo collided on the way in for landing. The sad part about the later crash is that it was a father and son who collided and the son was the one who died.
The president of the International Council of Air Shows made a PR-effective statement. However, looking into the history of airshows makes them look rather dangerous. (http://en.wikipedia.org/wiki/List_of_airshow_accidents)