What if you have more than one iPod?

OK, this is a theoretical question, because I don’t have a single iPod, and even with the new iPod Shuffle I don’t plan on getting one. But I wonder what happens if you have more than one iPod per computer? Does the new lower-priced Shuffle coexist peacefully with its more expensive brethren? Aren’t there some protections built in expressly so you can’t share more than one iPod with a single computer, or vice versa, to avoid people sharing their entire music libraries indiscriminately? Yes, I’m clueless on the details, and partially informed is probably worse than uninformed here. But someone let me know.