To me thats the best reason to go wider then 16x9. A little wiggle room can help in the edit.
Wheat, what did you actually crop to in the end? Although you make a good point (it's something I have considered (and tried) in the past), did you not worry that, not actually planning for a wider movie, you would risk being forced to crop certain bits that you didn't want to lose, or leaving yourself with too little headroom?
I'm thinking, for my own project, I will shoot 16:9, so everything is safe, then see if I can get away with cropping to 1.85:1, just for a bit of a wider look.
p.s. And while this is all good, I still have no explaination for my "Scream" DVD?!? Can anybody suggest why it's so wide? Does anyone else own a copy of "Scream", so they could check their version out?