There is still a chance users will get their files back, but it is not a foregone conclusion.
According to Freak, Pirate Parties around the world are preparing to file an official complaint against the U.S: "The widespread damage caused by the sudden closure of Megaupload is unjustified and completely disproportionate to the aim intended."
Additionally, "For this reason Pirates of Catalonia, in collaboration with Pirate Parties International and other Pirate Parties, have begun investigating these potential breaches of law and will facilitate submission of complaints against the US authorities in as many countries as possible, to ensure a positive and just result. This initiative is a starting point for legitimate internet users to help defend themselves from the legal abuses promoted by those wishing to aggressively lock away cultural materials for their own financial gain."