Alexander Skarsgard may not get to wield Mjolner but he's going to get to fight aliens on the high seas in Peter Berg's Battleship.  The True Blood star reached the final round of casting to star in Marvel's Thor, but the role ultimately went to Chris Hemsworth (Star Trek).  Tonight, Heat Vision reports that Skarsgard will star opposite Taylor Kitsch (Friday Night Lights), and will play "Kitsch’s brother, a straight and narrow naval officer whom Kitsch, a wildly spirited naval officer, idolizes."  The flick is based off the classic board game but instead of putting pegs into plastic boats, it's about an international fleet coming together to battle extraterrestrial invaders.Skarsgard is also attached to star in Lars von Trier's Melancholia and Rod Lurie's highly ill-advised remake of Straw Dogs.  Battleship is slated to open on May 18, 2012.