I'm not sure last night proved much but the discussion this morning on MLB XM went a long way towards persuading me. Statistics show that third time through the lineup offensive production increases dramatically and so the trend is going to be 5-6 innings for a starter. So the relief pitcher, and especially long and mid relief, becomes much more important and starter correspondingly less. The question then becomes why do we pay a guy $30M to go 5 innings? And the answer is, we won't be seeing that any longer.
You pay the starters for the regular season. You can’t win in the playoffs if you don’t make it. Bullpen importance takes on more importance in the playoffs. You can’t have your starters going 3 and 4 innings on a regular basis over 162 games. It would kill the pen.