Bug 134740 [Wizards] PDE product wizard is not obvious to use.
see attached image. The wizard for creating a new product opens with a file name initialized to ".product" which is selected. Generally this would imply that this is a good default but if you start typing you will replace the text with something else that is also a good name. If you require an extension for a file you should add it yourself like the "Export Archive" wizard.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/misc/ResourceAndContainerGroup.java
* Returns an error message indicating the current problem with the value
     * of a control in the group, or an empty message if all controls in the
     * group contain valid values.
     *
     * @return java.lang.String
     */
    public String getProblemMessage() {
        return problemMessage;
    }
    /**
     * Returns the type of problem with the value of a control
     * in the group.
     *
     * @return one of the PROBLEM_* constants
     */
    public int getProblemType() {
        return problemType;
    }
    /**
     * Returns a string that is the name of the chosen resource, or an
     * empty string if no resource has been entered.
     * @return The resource name
     */
    public String getResource() {
        return resourceNameField.getText();
    }
    /**
     * Handles events for all controls in the group.
     *
     * @param e org.eclipse.swt.widgets.Event