I mentioned yesterday that the Hard Rock memorabilia application was live already at http://memorabilia.hardrock.com. The AOL Silverlight-based mail client is not live yet, but they've just opened up their pre-registration site for testers who want to be the first to try out the new application, in just a few weeks' time. You can sign up here: http://ria.mail.aol.com/.
In case you didn't see the demo of this application either at the keynote or online, it's cool because it shows how Silverlight isn't just about flashy gradients or animations, but it's emerging as a solid RIA framework for building web-based applications that have the performance of a desktop application. It's not that you can't build a mail client in AJAX, obviously, but having client-side compiled .NET code, isolated storage for caching and a powerful rendering engine that supports control templates means that you're not relying on a chatty back-and-forth with a high latency remote web server. I've been using the application first-hand for demos over the last week, and there's nothing like it for performance - being able to flip back and forward in milliseconds from folder to folder takes all the pain out of web-based mail. This application makes AOL a real contender in the free webmail space, and it really raises the bar for the experience that users will expect from a web-based mail interface.
Make sure you sign up!