Apple Refurbs are my favorite product! I've bought iPod's of various flavors and a MacBook Pro. As previous posters have said, it's the same warranty as new, and when they arrive they are packaged like new. No issues and I'm very happy to have saved from 15-35% on my Apple products.
The only thing I'm aware of that you can't do when buying a refurbished iPod is have it engraved, but this is not worth the savings to me.