Stuart Benjamin at The Volokh Conspiracy suggests:
Playoff seedings are determined by regular season records. If (as in the NBA) 8 teams go to the playoffs from each conference, the team with the best record will play the team with the 8th best, the 2nd will play the 7th, and so on. The idea is to reward the teams with the best records by pitting them against the weakest opponents. But a better — and more interesting — system would allow the top seeds to choose their opponents.
NewMexiKen thinks this is a great idea.