"Whether it's enforceable or not, I don't know," said Schumacher when asked about the new rule at a news conference at the A1 Ring. "Certainly the obvious team orders will be enforceable and we made a clear statement from our point of view on how we are going to do things. There is nothing else to add."
Read between the lines and Schumacher is saying: We will be conducting business as usual, but will be much more subtle about it. There's always any number of unfortunate "accidents" that can befall a car. (like extra long pit stops).
I can't remember the specifics right now, but I have a vague recollection of a championship contender who's car broke, the team manager called his other car into the pits, had the driver get out, and the driver contending the championship was allowed to continue in his teammate's car.
I thought that was the whole reason for fielding a multiple car team; to use the greater numbers to ensure victory.