Why do we play football in the rain but not baseball?  I'm not suggesting MLB did something wrong by suspending game 5 of the World Series last night - but it's still an interesting question.  I've heard the following from friends, but have never heard anything officially from MLB:

• Lightning: Traditionally baseball was played more in open fields, so lightning was a real safety concern
• General Safety: The game gets significantly more dangerous in the rain (e.g., bats fly out of batters' hands, people can't see a 90 mph ball coming at their head, etc...)
• Game Integrity:  The game simply wouldn't be the same, and hence all parties would rather not play (e.g., missed infield pop-ups, ground balls hitting puddles, etc...)