1) Is the HTML wrapper called Main.htm or Main.html?
2) Is the url correct? The document has testworkspace not testWorkspace, as long as your consistent it should be ok.
There is a simpler approach you can take though. When you create your project, or modify your existing one, you can set the Output folder to your [JBossPath]/jboss-webtomcat../ROOT.war/testworkspace, therefore you don't need to copy the bin directory to the testworkspace directory as it will automatically compile it to that location. The second thing you can setup is the Output folder URL to:
http://localhost:8080/testworkspace. Both of these settings can be configured on your project via, Right Click your Project -> Properties -> Flex Builder Path.
When you have configured these options you can simply click Debug Flex Application or Run Flex Application from Flex Builder.
