When using Flash + AMF remoting I've always typecast the event.result as XML(event.result). Typecasting isn't working in Flash Builder, I'm getting an object as the result [object MYXMLROOT] and I can access it's properties, but I can't typecast it as XML, nor can I loop each of it's properties....
Oops, I'm using the wrong service, and meant HTTP. Why can't the HTTP service pass variables and return XML?
There are ways to use XML returned by Http Service in flex. Is this what you are looking to achieve?
The DCD features of Flash Builder 4 can also be used to access the XML as Services.