The big question is, have the distance gains really leveled off, or are we going to see another jump, like we did before 2003?
I don't think you are going to see another jump, as we did at the end of the 90's. The governing bodies have committed verbally that if there is a substantial increase from now forward, they will demand changes to counteract it.
Therefore, they're equally committed to denying whatever change there is. The main one being that in 2002, nobody was trying to reach 600-yard par-5 holes in two, and today, you see it from a bunch of the longer hitters. Somehow, they've gained 30 yards in two shots over that time. Maybe it's all on the second shot, but I doubt it.
And of course, the real problem is that they let the cat out of the bag throughout the 1990's, and then grandfathered it all in and declared 2003 the standard going forward, as if distance wasn't a problem for golf courses in 2003.