What is Ajax really?
A web page sitting in a browser can act much like any program on your computer, and often even better. Look at Google Maps. Accessing a large database over the internet is a great idea. Keyhole does this on the desktop too, but Google Maps might be even easier to use than Keyhole itself.
I think there's a lot more that can happen here beyond the benefits of retrieving data. Forms can be submitted to a hidden IFrame, allowing the web page to add records to the database. Or with Google Suggest, even the interaction with form elements can be enriched.
It's time to take a look at the web applications we have around now and figure out how Ajax can be used to improve them. This'll be a major turn in what the Internet has to offer. It turns out standard web technologies achieve what Flash and Java have done, but with much smaller file sizes. I really think this is the color-television revolution of the internet.