Good luck actually making it happen if it does somehow become necessary! If they can't reach agreement about anything else, I don't see people agreeing on spliting the Satoshi.
Without having to come to any agreement, just add mili/micro (or some other unit that is smaller) satoshi and the problem would be solved. I can see how it would be hard to reach an agreement on the name though.
Otherwise it won't be needed. Now even if it does become the world's only currency, dividing the Satoshi into a million Laudas won't be needed: one more decimal will do the trick (to which we'll add 2 more for the sake of clarity).
If you do not use Laudas, I will stall consensus for all eternity!