(News from the Ether)
Nasim Mansurov has an interesting post in which he considers how long the shutter of a camera will last. Your camera will have a specified number of clicks the manufacturer expects the shutter to last. A reader asked him whether she should replace the shutter on her camera because it was approaching that point. The short answer was No. A shutter can fail at pretty well any time but for most cameras it is likely to last far longer than the manufacturer specifies, longer than you will have the camera for most people. Nasim also provides a link to a very interesting database by Oleg Kikin with data on shutter life expectancy for various cameras.