The gun laws in Canada probably don't impact too much on the Olympic shooting events. As I understand it, bolt-action rifles are classified as non-restricted firearms and simply need to be transported unloaded and locked up when not in use. Since there are no pistol shooting events in the Winter Olympics, the athletes don't need to deal with the more stringent rules on restricted firearms.
The bigger deal is with the 2012 Summer Olympics, in London. There are pistol events in the Summer Olympics. British laws of course ban all handguns in England, Scotland, and Wales, so the British shoter have to go abroad to train. I hear there will be a temporary relaxation of the handgun ban for the athletes during the Olympics.