I found a nifty plugin for Firefox that enable you to see intelli-sense in the Firebug Console.
If you want to enable intelliSense for Dojo, jQuery and JavaScript on the firebug console you can add the following plugin to Firefox, under Firebug. This enables you to use intelliSense in firebug.
Get the Firebug auto-completer Plugin
Firebug Intellisense for dojo jquery