It'll be interesting to see how things change because of the internet. Because of the internet people are accustomed to a much faster rate of change of companies and brands and websites they find familiar. In the age of the web you might have to re-brand yourself to stay alive. Many failing commercial brands have re-branded themselves in the past even under an entirely different name and done quite well for it. But then you see labels like Coca-Cola that haven't changed much in a very long time.

I'd say on the web you've got a bit more latitude to update your logo as long as it sticks to the same theme and similar color scheme so that people still recognize your brand immediately. That's if your a company who's logo is actually on their products that are being distributed to people. If your logo is just on your website and no one see's it because you only provide services and not any merchandise.... people may not be so attached to your logo and you are likely to be free to change it without serious repercussions.

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