Why is Japan suddenly the greatest other power in baseball? Granted, they won the WBC last time and may win again, but I'm sure Cuba, Puerto Rico, and other countries would object. Also, what about players from Japan that are already on MLB teams? What if, say, the Mariners win the World Series, and were to play Japan? Who would Ichiro play for? This idea of yours has so many holes in it, it's completely unfeasible. Again, though, I think you're just taking the phrase "World Series" quite too literally.