Here's one of the things that bothers me about AJAX. Some of it makes sense. Add a bit of XMLHttpRequest here and you can build a CSS compliant popup that subscribes to an item without reloading the page. No brainer. Some of the other stuff really makes me scratch my head. The way gmail uses a hidden iframe to get around the history and back button issue. These are hacks. Now we have toolkits which ship based on these hacks. These toolkits will be deployed on production sites which people depend on. Next the browsers will be updated and might not work with the hacks anymore and your nice webapp will break before its time. We still have people running Apache 1.x. People run production sites on Linux 2.2 and love it. Stable code. I suspect we'll have perfectly good apps that just cease to function because the developers have moved on or the site can't afford to pay new developers to work around the problem. I think the interesting part of Ajax moving forward is the Zen of the ideal solution. Finding the right amount of Ajax to add to your site and staying away from the risky areas. Of course one good thing about some of the "house of cards" AJAX hacks is that the push the browser vendors forward. Microsoft of course being the biggest culprit of resting on their laurels