On the official site (Heavenlysword dot com), the 5th and final animation has come out and they are all pretty cool if you haven't been watching from a while ago its definitely worth a look. There are also 5 making ofs which came out at the same time as the animations when they got released one by one which show so nice stuff about the game.

The animations show the story behind the sword and the legendary warrior right upto where Nariko is born and steps in. They are done really well and I can't wait for the game now... Not too long

Thanks for posting this. I really do enjoy the animated series.