I’ve enjoyed the new release of Snow Leopard for a while now, but just attached my iPod nano for the first time. Darn thing didn’t seem to want to show up in iTunes. It did it Finder, so there wasn’t anything wrong with a cable or the iPod itself.
Google/apple’s support-site didn’t say quite a lot about it, but I found the solution: Pop your Snow Leopard DVD back in your player and start the ‘Optional’ installer. You can select ‘iPod Support’ in there. Once the installer is done, restart iTunes and reattach the iPod. It is now back in iTunes.