Not too sure I know exactly what you are trying to do, but another tab in the same browser (for IE and FF anyways) are still in the same session, so if you want to open multiple tabs of the same view you would need the following context param in your web.xml.
<context-param> <param-name>com.icesoft.faces.concurrentDOMViews</param-name> <param-value>true</param-value> </context-param>
If you have the view in Session scope, you would still have the same view in both tabs as well. Since 1.7.2.SP1 is currently recommended, I will assume this is the version you are using. Advice would be to use jboss-4.2.3.GA for a while longer as well. ICEfaces-1.8 is targeted to support jboss-5.0.0.GA fully.