On Confidential this week, they did a feature on the making of that commercial, and the guy slipping was an accident.. they decided they liked it so much though that they had to use it in the finished product. Ah, the joys of commercial making.
It won't be Big Show (knocking on wood right now). His back is in terrible shape, and probably won't be able to work in the ring for more than a couple of minutes. Does Vince really want a three-minute World Title match at WrestleMania?