I've got a video ipod that's 8 years old and works fine. However, the li-ion battery was basically dead after 4 years, and designed to not be user-replaceable. Luckily, i can use it in a dock, but I'd need a heck of a long extension cord to jog with it.
That's very common for portable electronic devices now. I expect my 1 year old tablet to be effectively dead two years from now, due to a non-replaceable battery and probably a non-upgradeable OS.