Macromedia Flex - anybody

A recent JDJ magazine came with a trial copy of Macromedia Flex - a new development environment supporting Flash on the user side based on a XML definition of the user interface, and a Javascript-like user-side event handling language. Your user interface can grab XML data - SOAP included from the server to present to the user.

On the server side, it runs on Tomcat or a J2EE server. Based on the jar files installed, it is using a lot of Apache SF open source toolkits, but the compilation to something the user side understands is proprietary.

I am going to be experimenting with this so I thought I would see if anybody else is using Flex. Advice? Good sources? etc.?
Bill