The new episode of Mythbusters aired tonight. Big sequence on the movie myth of a sword 'slicing' another sword. They brought in some individuals that did cutting to measure speed and force. Some nice footage of cutting tatami!
The only sword that was broken/cut on impact was a 440 wallhanger by a quality katana. Everything else survived the attempts from side and blade to blade. They also brought in a claymore, a 'viking' sword and saber.