These types of chain letters have been going around forever... the first time I saw it, it was "Bill Gates is trying to track e-mails across the Internet, so forward this to all your friends and Microsoft will pay you $5 for each person who receives it."
Also, if you actually read the message, they aren't trying to scam anyone out of money, they're just trying to get the chain letter sent out to as many folks as possible... It still doesn't make sense, but at least it's not as bad as using the baby to sucker old ladies out of their retirement fund.