It's all about egress. Getting from the clubhouse to #10 tee for a start would involve a cart ride on the same paths used by spectators, and there isn't a lot of room. At Olympic it is pretty common to "just play 8" if someone is playing casually and doesn't have time for 18. If you have more time, but still not enough for 18, you can play 1-10, and then 7 and 8, or 1-9 and 18 back in.
Joel, I worked #9 in the '98 Open and the club of choice then was a 3 wood, even for short hitters like Faldo. There really isn't a need for a driver off this tee....the fairways are so firm and players will want to hit a cut so I would imagine that many or most will use a 3 wood this year.