There are corrections to this story.
One of the biggest problems with Web-based applications is that they don't work when you're not online. As James Fallows notes, Web 2.0 becomes Web 0.0 when you don't have access.
Google Calendar is a great Web-based application, but if you want to use it when you're not connected to the Web, you're out of luck. Or are you? A Canadian start-up, Time Search, has released an early public beta of Calgoo, an offline reader for Google Calendar. It downloads your appointments from Google onto your local PC and has its own decent calendar interface.
At this early stage, the application is a bit rough. While the application supports multiple calendars (for example, you might want to use your calendar, your spouse's, and the baseball schedule), and can easily switch between them, I couldn't get it to actually display multiple calendars at the same time, which would be very useful. Also, it doesn't let you create appointments. Hopefully, that function will be added in a future build.
I would like to see either more stand-alone apps like this or, better yet, micro local servers that run on our machines and synchronize with online data so that we can access our data no matter whether we're online or off, using just one interface, not a different one depending on our connection status.
See also the new offline blog writer from Microsoft, Windows Live Writer.