First, I have to declare that I'm surprised that distance has become so important. Started streaming the Golf channel, and then realized that US marketing appears to put a lot of emphasis on distance and swing planes, rather than say accuracy and or consistency.
Nevertheless, in a bid to add a bit of data to this discussion I took note of the drives at the range today (a bank / public holiday in South Africa).
On average, 20 - 50 year old males, hit their drivers near the 218 - 250 yard mark (no ball roll).
The guys who did attempt to hit it long were under 30 (like me) and were pushing the balls wildly left or right. Their shots were oft accompanied with laughter, I don't trust golfers with poor etiquette :)
The two guys who were doing drills and one could tell had a practice regime were hitting their drivers consistently near the 250 meter (280 yard) mark with soft draws, so with roll likely to get near the 300 yard mark.
There were two guys (of the 30 or so) consistently clearing the 250 meter range marker, with range balls - they shared a Pro coach, and were around the 6ft mark.
For nearly two hours, only 10% of the golfers at the range at a well supported club in Johannesburg were able to consistently hit it anywhere near the 300 yard mark with any amount of accuracy.