there is never live ammo on parade and there wont be in the future. getting attacked by terrorists is one thing, getting shot by a soldier you are supposed to be inspecting is quite another. the security level inside and around Beijing is as high as it was during the olympics, Hebei province is described to be a bufferzone against terrorists from outside of that area. the "anti-terror,protect the capital" campaign goes as far as Guangdong province, on the day of the parade there will not be a single person on Tiananmen square that the security team does not know about.
Sadat's assassination happened during a parade, but I don't think those soldiers were supposed to be carrying live ammo in the first place.
According to one article read on Xinhua news, the air force did carry live rounds during the first Chinese national day parade in 1949 (and this year's the 60th).
because Chiang Kai-shek planed to send bombers from Taiwan to bomb the celebration, in the time PLAAF total only had 9 fighters, and those fighters would attend the parade, they had to carry live rounds to defense.
Chiang Kai-shek final cancelled the plan because the flying range is too far.