I'm still catching up on Web 2.0 news but one of the interesting bits was that Bungee (my coverage), the platform as a service company which lets you build, test, deploy, and track Ajax applications from a browser-based application, is now leveraging EC2 so that Bungee developers can deploy their applications on Amazon's EC2. Previously when you deployed a Bungee application it was deployed on top of Bungee's architecture. This new move provides a really great way to scale and could possibly open up a larger community of Bungee developers who come to the platform via Amazon.
Along similar lines, Bungee is now allowing developers to deploy Bungee-powered applications on top of their own server, something called Bunge Application Server, which uses VMWare technology. Both of these are going to be available in June.
I don't believe either one of these lets you actually host the IDE, so you'll still be doing all of your development on Bungee's servers, but with the new deploy options integrated directly into the IDE, it should be very easy to take your creation and use EC2 or your own server. I think it's a great move that keeps Bungee's core assets (like the IDE and platform) at the forefront and allows them to use other services to actually scale the applications. As Bungee gets more popular I don't know if they wanted to eat the cost of storing all those apps themselves. Now they can keep on trucking with Amazon as the hardware backbone.