On Xbox.com there is new news of how you will be able to earn those achievement points you will want to get. It looks like it will be a little harder than some games as there will be achievments based on which faction you enter into and whatnot.
Much of the side-stories and quests found in the world of Tamriel stem from the various factions you’ll find throughout the land. Within each faction (e.g. the Thieves Guild) are different ranks. You’ll unlock an achievement for each rank you find yourself promoted to. Not only does this offer much in the way of variety, but you’ll find you won’t be able to join each faction in one play-through. Therefore, you’ll not only find different achievements when you play through as different characters, but also entirely different chains of quests and storylines.