Can you use the
Ctrl + Alt + Delete, keyboard combination to produce any other screen? I've heard of this happening a couple times in forum posts and sometimes that key combo works to break the stalemate
It sounds like your laptop is hung and is not actually shutting down completely.
How long has it been in this current state? Do you see any hard disk activity light (assuming that the laptop even has a HDD activity indicator)? Can you hear any disk activity or anything else that would suggest that something is still going on?