Is that what Bloodmoon was all about? I never played any of the expansions for Morrowind...
Yea. The Main Quest of Bloodmoon was of Hircine conducting a Hunt he does every Era in Nirn. In this hunt, Hircine arrived with his werewolves to prey upon the inhabitents of Solshteim. In the game, he chose four great hunters worhty of being in his last hunt, one of which is you. So you have to face him in the end of the game. Yu can ever become a werewolf and serve him.
But I would love to see an expansion the size of that Shivering Isles stuff in Oblivion. I hope we get to see Hircine's Realm and hunt there as a werewolf. Or for the other players who dislike being a werewolf and werebears, run for their lives. But I doubt it, since Bethesda said the DLC will be like Fallout; Short and insignificant.