http://elderscrollsonline.com/en/news/post/2013/05/01/journey-to-coldharbour
Highlights:
Molag Bal is now the "God of Schemes", I guess to keep the game in PG-13 territory. Understandable I guess, kinda makes me think of http://upload.wikimedia.org/wikipedia/en/9/9f/Boris_natasha_fearless.jpg though.
"As in all the games of the Elder Scrolls series, in The Elder Scrolls Online there's a cosmic threat to Tamriel." -Lawrence Schick, seemingly ignoring three (arguably four) of the five main TES storylines.
"There is an ancient prophesy in the Elder Scrolls that says the Soulless One will thwart Molag Bal's plan - and in fact, the player is the Soulless One." -Wynne McLaughlin, looking very pleased with himself.
"The player must go to Coldharbour... and find out where his soul is being held and why. What is so special about his or her soul that Molag Bal keeps it secreted in such dangerous places and under such mighty wards and guards?" -Lawrence Schick (so... every player is magic and special? Doesn't that kind of defeat the point?)
On the plus side, Coldharbour is very nice visually. I like the long chain gangs of enslaved mortals - not terribly subtle, but subtlety isn't really Molag Bal's strong suit anyhow. And we got a glimpse of a few new enemies - a palette swap of the flame atronach, a corrupted spriggan that's rooted to the ground, and some kind of new Daedra that looks similar to a dremora or mazken. I'm a little concerned that the Daedroth wasn't present, but we've seen it in screenshots before so we at least know it's in. I'm mostly concerned that after Oblivion, Zenimax has forgotten who the Daedroth actually serves.