Sega's official video game of the 2008 Beijing Olympics is looking pretty damn realistic, if these screenshots are any indication, but as Olympic games of the past have taught us, it isn't about the looks so much as it is the motion. I am actually willing to take that a bit farther.
There will be no successful Olympics video game until they implement realistic hurdle-based testicle damage.
As someone who has felt the painful impact of a hurdle between my legs, I can safely say that making the runners simply stumble or slow down for hitting a hurdle does not accurately represent the rigors of the sport. It's the whole reason they implemented hurdles in the first place!