MY THOUGHTS Season 8: Who betrays Buffy?

In issue 10 of season 8, Anywhere But Here, we can see Buffy lying hurt, crying on the floor in a vision. The character Robin answers the real non-vision Buffy's question ("What happens to me here?") with;

"Betrayal. The closest, the most unexpected."

On slayalive.com we have tried to figure out who it is. The same person that is Twilight? Xander, Dawn, Willow, Giles, Angel, Spike, etcetc?

It could be "Future Dark Willow" from the Time of your life arc (#16-19) that Robin refers to, but I think that would be too obvious. I'm guessing that Buffy betrays herself.

Maybe she fails in saving her family, and feels that she has betrayed herself. Or maybe she realizes that she has become someone she hates. Maybe the part of her that is demon takes over, or disappears completely.

Or maybe the other slayers will turn on her, a la end of season 7. The people who she shares the most with turns on her.

What do you think? Tell me here.