Thats right! Not much information has been released about it, but apparently you can travel to all different parts of Tamriel including Skyrim, Morrowind and Cyrodiil. It is also set a millennium before the events of Skyrim when the daedric prince, Molag Bal tries to consume all of Tamriel into his realm.
The announcement trailer is here, voiced by Dumbledore himself:
Also, there as been a screenshot released:
Hidden/Spoiler:
http://www.gameinformer.com/p/elderscrollsonline.aspx
That link also contains the announcement article, which provides some information.
Now, what do you think? Personally I wish that Bethesda and ZeniMax had stayed with the Singleplayer RPG genre instead, but a small part of me has always wanted to play Elder Scrolls games online with friends. Bethesda has always had really deep lore within their games, and hopefully they wont drop/bend that lore to fit in with this MMO. So yay or nay?