Even though Google offers many web applications that could replace traditional software, the integration between them is barely visible. The closest thing to an online desktop that displays your favorite applications is iGoogle, where you can set up themed tabs.
To switch from Gmail to Google Calendar, you’ll click on the navigation bar and open a new window or tab. While you can always resize the windows and keep both Gmail and Google Calendar visible, it would be nice if iGoogle provided a way to freely move the gadgets inside the window, like in yourminis.com.
With the addition of Google Desktop Gadgets, and the customizable layouts, the personalized homepage could really replace your desktop. But gadgets need to be more powerful, offer more than a list of links. Ideally, the Gmail gadget should have an expanded version that lets you read messages, compose mail and search inside the archive.
think that it would be a good idea for Google to group all of the online applications in to a single web application. Something like an eDesktop.