Right now, operating systems run on your computer. Period. Sure they can access the internet, but it is not used as a core component of the OS. Here are three reasons why this must change and why it would be good for Linux:

1. It is inevitable. While the people who say that cloud computing is not reliable may be right for now, I think there is little doubt that cloud computing is the future, at least eventually. That means that either operating systems become irrelevant or they adapt to work with the cloud.
2. Linux could be the first. No operating system has managed really deep integration with the cloud. I am not talking about the applications that let you interact with the web application on your desktop, but rather about deep and seamless integration right into the desktop. For example, perhaps folders might be transparently stored online or just by importing photos to your computer they would be put online. This sort of integration could be the biggest new feature since the GUI. And Linux could be the only one to have it.
3. Open-source has a huge advantage. People like to know that their data is safe, secure, and private. With closed-source web applications, this basically means trusting the provider. With open-source, on the other hand, you can rely on independent reviewers/programmers to verify the safety of your data.

Because of these three major reasons, I sincerely hope that there will be an effort to bring Linux to the cloud world in more than a skin-deep way