The grim, macabre, or just curious iPod owner might want to pop over to the iPod Death Clock at iPodMechanic. Type in an iPod Serial Number and answer a few questions about general usage to see how long your iPod has for this world. My 30GB iPod video is due to croak in about four months, dammit.
You don't actually have to type in your own Serial Number if that sort of thing gives you the heebie-jeebies. The number is used to determine the iPod model only. You can also use one of the dummy numbers they offer on the main page.
This is for entertainment purposes only. I certainly hope my iPod is going to last into the next year. I'll let you know around April whether the death clock was right or not.
Update: link seems to be dead. The page now loads with this message: "Sorry, we're not ready yet! Should be a tasty Christmas present for you :) Please check back soon!" Bummer.