The Elder Scroll Online (probably many questions, yes?), and ZeniMax has a few answers in return. The developers took on a half-dozen queries from the community, many of which were concerned with setting and story, not to mention why typical adversaries are working together all of the sudden.
If you're concerned that the three factions will offer thinly veiled copies of each other's quests, the devs have good news: "Each Alliance's content in TESO is as varied and dynamic as the Alliances themselves are -- your adventures an Argonian in the Ebonheart Pact, for example, will be quite different than those of a Bosmer in the Aldmeri Dominion."
Another player asked how similar places will be that are covered in both the single-player titles and the MMO; the devs replied, "The stories and events that unfold in these areas during The Elder Scrolls Online will be different than those in past Elder Scrolls games. The people living in these familiar places won't be too different from their brethren in later times; however, they will have different views and tales to tell, based on the current events that are impacting their daily lives."