Well, nobody is going to believe this, at least in the contested areas, for a long time to come. As I write this writeup, Bush is ahead of Gore in the Florida recount by 341 votes. This is a ridiculously small amount, easily within the margin of error (ie every recount would likely come up with slightly different results, and the variation would probably be enough for a different person to be called the winner after each one).

But because the difference is so small, no longer will people, at least in the state of Florida, feel that voting for a third party is ok because their vote does not matter. It doesn't mean they can't vote for a third party, but the "your vote doesn't matter" idea will be demonstrated to not be applicable.

My guess is that this election will increase voter turnout in future elections because people will see that they can matter.