If the Internet was around when I was a kid, I think i would have gone on a lot more dates. I'm guessing someone will do a historical study that shows that the Internet has had (or will have) a massive impact on dating/mating patterns, pregnancy, STDs, and basic human development when it comes to "coupling". My guess is that it radically changes the psychology of dating -- making people realize they have much more "opportunity" than they thought they had before.
The famous pre-Internet stat is that x % of people marry someone with x miles of their home. Will that still be true?
Did culture seem more monochrome... did more people listen to the same music, think the same thing? Or has access to the "long tail" in ideas, music, whatever, really spread more points of views? Before the popular web was there more A vs. B thinking and now there's more A, B, C, D and Z?