With the advent of Firefox 3 and next generation browsers are going to revolutionize how we see the web.
Take note of the WhatWG offline storage spec:
This will allow developers to essentially author web based applications that run like desktop applications. Of course the bonus being it is a webapp, is that instantly it will run on all platforms that have a modern web browser. Imagine a re-write of the online google office apps that allows you to work on your documents offline, but then as soon as you connect everything is synchronized, backed up, and stored online. Thinking this through this metaphor can hold true for just about any desktop application.
I am really interested to see how synchronization will be handled. Will this be accomplished by some standard protocol or left up to the end developers to implement their own engines?