New York Times designer Khoi Vinh has a great entry up about the need for "Designed Deterioration," which is different than planned obsolescence in that the former hopes an object actually improves through aging.
I've noticed recently that the concept of what we might call designed deterioration is fairly anathema to digital hardware. The objects we purchase from purveyors of digital technology are conceived only up to the point of sale; the inevitable nicks, scratches, weathering, and fading they will encounter is not factored in at all. The result is that as they see more use, their ignorance may recede, but they wear it poorly. They don't age gracefully.