I would hate to go back to just having the best team in each League in the playoffs. One 7 game series at the end of the season? 2 teams out of 30? No way.
Even going back to just a league championship series is equally unenjoyable to me. I remember back to 1993 where the SF Giants won 103 games, the most in franchise history since 1905, and did not even make the playoffs. It should be very, very difficult for this to happen (almost impossible).
Many people who are "traditionalists" hated adding the extra wild card team, but honestly I dont understand why. With one wild card in each league there is no advantage to winning the division, now there is a huge advantage. This is much better. I would much rather have the "play in", if it helps to think of it that way. I hate to say Bud Selig did something correct, but in this case he did.
The current system requires a team to be in the top third in each league (more or less), hardly excessive. It isnt like Hockey or Basketball where half (or slightly more) make the playoffs, it is pretty close to Football (slightly more than baseball at 3/8 of teams make the playoffs). If you don't count the loser of the "play in" wild card game it is even more restrictive (4/15, 27%). That seems pretty reasonable to me, I don't want the playoffs to only last 1 week.