Just in case there is a battery problem in 18months the extended warranty covers it for 2 extra years.
AppleCare for iPod

I have had my ipod for quite some time and the battery still works great.

The irreplaceable battery was the reason I bought a Creative Jukebox III. That and the price!

more buzz generated - news

Two filmmakers are getting attention around the Net for an "antiadvertising" project aimed at protesting what they call the "dirty secret" of the iPod music player--its battery life.
Brothers Casey and Van Neistat, who collaborate on video projects using Mac editing software, said they were told by a technical support representative at Apple Computer that the cost to replace the dead battery in an 18-month-old iPod would be $255--comparable to the cost of a new device. Irked at what seemed to be the early obsolescence of the music player, the brothers trekked around New York City stenciling the words "iPod's unreplaceable battery lasts only 18 months" on all the iPod posters they could find.
Now the Neistats claim that the video they created of their exploits is getting 50,000 hits a day on the Web site Ipodsdirtysecret.com. As of Wednesday afternoon, the site's traffic counter indicated it had seen more than 194,000 visitors.
As it turns out, it's possible to replace the battery for as little as $49 using third-party kits.