Cricket is not an Olympic sport even though London has held the games several times and will host again in 2012. Sydney and Melbourne also had the opportunity to bring Cricket to the Olympics as at least as a demonstration sport.
I was referring to Yankees, Giants, Orioles, and Red Sox playing in the world cup to bring it more on par with the FIFA world cup, ie the best players in the world playing for their respective countries. But you knew that.
In case you didn't realize the jist of my explanation, the reason that it is the "World Series" is because of legacy or if you like better tradition. In 1903 the leagues in the Series could arguably be considered the best in the world.
The World Wife Carrying Championships is held in Finland or Sweden somewhere, even though I'd bet somebody in Zimbabwe could compete and win. But they still call them "world"