Stop thinking of a web application as a collection of pages.
The back button is not a bug in Ajax, it’s a flaw in the browser metaphor.
I hearby serve notice to the following browser controls: forward, back, home, reload, and that URL field. You need to die… unless I need you. These controls are (rightfully) designed around the idea of the web as a collection of pages, but an application is collection of objects where you, the user, are guided by a well designed interface to get your job done. We don’t actually need to kill these controls because they do serve a purpose, but the web application developer should be able to choose when they’re available because the developer is designing the application and they are incented to do what’s right for their users.
No. The perfect web application will never be a direct replacement for your favorite native application. The medium, the technology that is the Internet, will always change the content that it delivers, but web applications are still in the dark ages. Take a leap with me and think about web applications that do not compromise in user interface, that do not settle for interaction models designed around a clumsy metaphor. All the richness of the best desktop application belongs in web applications…. all you gotta do is want it.