Looks like another WoW-clone with an ES paint job. It's immediately evident from the singular released screenshot that Zenimax Online studios isn't Bethesda Game Studios, and they don't really get what makes the ES games special. The music in the teaser was as un-epic as the music in the Skyrim teaser was epic, it's in third person, and compared to other things like say, GW2, it looks rather bad.

So, the question becomes; will TES VI be sabotaged by the release of ES online? Will unnatural things be required of BGS by the publisher? Will the franchise lose it's sterling reputation via the release of Yet-Another-WoW-Warhammer-clone? Will gamers be able to keep the fact that BGS and Zenimix Online are separate divisions within the same publisher in mind and not allow the anticlimix of ES Online affect their perceptions of the real games?

What do you guys think?

Everything is possible in this economy in big corporations like these, but I think nothing bad will happen to the single player series except some lore luggage that has to be digested. By the time they start working effectively on TES VI (2014? 2015? depends on howFallout 4 goes) this mmo could be already dead and buried (aka free to play).