A rebel alliance of demons thought they could overthrow Satan by using the sword of the Archangel Michael in "Rebellion", an episode of 'Reaper'. However, the Devil laughed off the threat and showed them all that the sword was just a cheap prop. He couldn't believe they thought he'd just leave Michael's sword laying around.
The Devil made it sound as if he actually had the sword, a weapon never far from Michael's hand in most of the pictures of the Archangel. But I don't think Satan ever had the sword in the first place. I think Michael has it and still wields it.
We've seen Michael the Archangel in 'Hercules: The Legendary Journeys', and in 'Xena: Warrior Princess', as well as in the 'Fallen' mini-series (although I could be wrong on that). And I don't think he's loosening his grip on his sword anytime soon....