I know this topic was flogged to death yesterday, but I thought I'd add a few comments.
I had an interesting discussion with a friend of mine yesterday, about how the regular season itself essentially used to function as the playoffs, with the two best teams in each league battling it out for the right to go to the World Series. And before 1969, there wasn't even a championship series. It's almost hard to imagine baseball as we know it now sending the teams with the two best records from the AL and NL straight to the WS.
While I like the cut-and-dryness of those halcyon days of the postseason, I also realized that, while I began to love baseball around 1988, my rabid fandom for the Yankees didn't really fully develop around until 1993-1994, when I really started paying attention on a daily basis. Which means that the last pre-Wild Card era postseason I remember watching was the 1993 World Series with Philly playing Toronto. Otherwise, my baseball zealotry has been at its strongest during the Wild Card era, and at this point three rounds of playoffs has been going on long enough that it feels like it's been that way forever.
Part of me does think it would be cool to go back to two divisions in each league, albeit keeping the four playoff teams from the AL and NL. I love that it could mean that three teams from a hypothetical 7-team AL East could make the playoffs.
As far as interleague diminishing the value of the World Series, while I don't despise interleague play per se, it seems silly now. For the first five years or so, it was a fun novelty, getting to see the Yankees face teams they've never played before. But, more than 10 years in, now that the Yankees have been to every ballpark in the majors and faced everyone at home during the regular season (with the curious exception of the Dodgers, of all teams), it seems superfluous and also arbitrary, especially since the way it's presently set up, you only face your geographical rival and a handful of teams from whatever division you're chosen to play against. And you don't even face every team from that division, which makes even less sense.
Assuming interleague play isn't going anywhere, I say that to keep interleague play relevant, get rid of the unbalanced schedule (honestly, I do not need to see the Yankee play the Orioles and Blue Jays each 19 times a year), and set it up so that every team in baseball plays every other team. How cool would that be, if you knew you could expect to see the Yankees play every team in baseball at some point throughout the year? It'd probably be logistically impossible to have home-and-homes against every team, but I wouldn't have a problem with the Yankees only getting to play some NL teams on the road if they had to, given that that's how interleague play is scheduled as it is.
On the flip side, I would also have no problem getting rid of interleague play, enabling the Yankees to play every team in the American League an equal number of times, while also reestablishing some distance from the NL. Non-interleague play was one of the many things that made baseball so unique from the three other major sports, and I do think you can make a case that interleague has cheapened the World Series to a degree. Playing the National League in the World Series definitely seemed like a bigger deal when you didn't meet that team in the regular season.