Currently you are not able to divide it beyond as satoshi is the smallest introduced unit. However, if it ever becomes needed, additional units could be added that are smaller than a single satoshi (e.g. 1 000 000 Laudas = 1 Satoshi). I don't think that it will come to that though.
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.
It is 1 billionth of a bitcoin anyway. At $100,000 per bitcoin , 1 satoshi would be worth 1/100th of a cent. I think it would be generations before it would be necessary, and then only because so many coins would be lost.