The stock JBP navigation portlet is pretty barebones. We replaced it with our own version which handled I18N for page names, explicit tab order, secondary navigation, and some other features.
I have a same situation as mmontoni. Would you please tell us , where can I get the JBP navigation portlet? Is it possible you send me a copy of it?
My email vcfgvcfg at 163.com
In 2.6 there are already i18n, ordering and secondary level for navigation out of the box
you can achieve this by creating a nested page/s, then when you point the mouse on top of the tab that has a nested page/s it will show a drop down menu