More and more applications are moving to the cloud: Google Docs for productivity apps, Meebo for instant messaging, Gmail for e-mails, Salesforce for CRM, etc.
Yet, I\'
I believe a very valid approach to web applications is to still keep all the browser features enabled, such as back button, opening things in new tabs, bookmarking, changing font-sizes, and so on.
The browser's right-click context menu is something that I do not want to have taken away by an app.
Now, when you start moving the web app out of the browser into its own window (turning it into a dedicated application, such as Fluid does, and I believe Chrome OS will), without URL bar and back button, then we can talk about the context-menu.