A contextValue parameter has been added to the panelGroup within the tree node:

<ice:tree>
               <ice:treeNode>
                        <f:facet name="content">
                            <ice:panelGroup menuPopup="::::j_id13:A" contextValue="#{item.userObject}"
                                `<ice:outputText value="#{item.userObject.text}" />
                            </ice:panelGroup>
                        </f:facet>
 </ice:treeNode>

The doSomething method will reference the contextValue here:

<ice:menuPopup id="A" value="Do Something">
         <ice:menuItem id="item1" onclick="return false;" value="Item 1"/>
           <ice:menuItem id="item2" actionListener="#{tree.doSomething}" value="Item 2"/>
            </ice:menuPopup>

and subsequently:

  public void doSomething(ActionEvent e)
    {
     ContextActionEvent c = (ContextActionEvent) e;
     IceUserObject i = (IceUserObject) c.getContextValue();
    }

The contextValue parameter that is passed is always null.