Could it be true? We'll find out in a couple months. I really don't know how I feel about this. I would love coop play in Skyrim though.
It really depends heavily on whether this plays to TES's strengths. Which ... may or may not apply in an MMO, I'm not really sure. For some reason I suspect a "good" outcome would resemble what might have happened if Darkfall actually worked. TES has never been really story-heavy; it's more a sandboxy game, and the talk of three factions might imply it's basically a giant pvpfest. Not a bad thing in an area the size of a TES game, but... there are many ways to make it suck.