http://elderscrollsonline.com/en/game-guide/the-alliance-war

Now, siege weapons etc are in. Cool features, but I'm hoping to see "guilds owned territories" as well.

But what worries me the most:

Emperors gain special abilities that increase their prowess on the battlefield. They are true leaders of their alliance, and a force to be reckoned with.

There's no Emperor, but emperors? Seriously, can't they change the name for a title that's more suited, such as an synonym for an army leader?

You should see it as A Song of Ice and Fire, every faction proclaims the "most suited person" for King (or Emperor in this case).

If that would be the case, I'd be declaring war within the factions as well, I sure as damn don't want a Nord or a Lizard on the throne!

Who knows, that might just happen some day. There are already faction leaders though.
I wonder how they'll work it into lore that instead of the faction leader a commoner becomes Emperor.

I think the use of "they" is to not the possibility of multiple people ascending the throne, not actually having more than 1 emperor at once.

Edit: too many windows open at once. IGNORE ME. To be relevant I'm pretty sure their wording was based on the fact that there will be many emperors in succession, by design.

Yep, their using Emperors in the grand scheme sense of the game. There will be only one Emperor at a time but over time there will be many who have had the title.