I once read someone who proposed the flipside for baseball:
1. Put all MLB teams in a single league. Let them play the regular season schedule similar to how it is now. Top team at the end are MLB League Champions.
2. Scattered throughout the regular season schedule would be an FA/League Cup-style tournament, with single-game knockout games with every team involved at the start, sorted by random draw after each round. The MLB League Cup champions would be decided in a final multi-game playoff series (best 3 of 5 I think) between the two remaining teams.
3. He also had some notion of inviting international teams to play a proper World Series every October, similar to the WBC.