From what I saw, there weren't really any spoilers. It showed that new bounty hunter, Mira, in action, as well as I think the white haired Jedi. None of the plot or storyline was shown, and none of the end bosses or returning NPCs were shown.
Yeah, the E3 demo "storyline" had nothing to do with the K2 game - it was a conscious decision.
The white-haired chick in the demo isn't Arren Kae - it's just one of the female PC heads you can choose. I don't think the "white haired chick" was in any of the E3 levels, and if she was, then she's a sneaky one.
Arren Kae? Thanks for that