Yes, computers do die. An average computer can last anywhere between 2-6 years. After a specific period of time, your computer will wear up and will no longer support latest software or accessories with it. This will be the time when you will begin the dread and inevitable search of finding a replacement.
Many have wondered if the iPad is a game changer. That is still a question to be answered, but it seems as though the entire world is ready for the iPad. Apps are ready, and so are sites, and even web services and specialized web apps like an iPad ready Gmail app.