99.9% of Websites Are Obsolete: "Though their owners and managers may not know it yet, 99.9% of all websites are obsolete. These sites may look and work all right in mainstream, desktop browsers whose names end in the numbers 4 or 5. But outside these fault-tolerant environments, the symptoms of disease and decay have already started to appear." [ranchero.com] [Mac Net Journal]

So, don't be on the cutting edge. Focus on content, not on the appearance. However, you could also argue that most of the web sites are never intended for staying up long - they are build to last a certain period, and then disappear before the next big fad.