I'm about to start translating the file to Spanish (Castellano, from Spain), as I don't see any posts here that show that it's been done.
There's a lot of chat about it, but there doesn't seem to be any actual finished translation (they should be here in this thread, right?).
Let's try to give Fortress Forever as much help as possible to gain popularity, or otherwise we'll never have an actual TFC followup to play in the future...