A great deal of people here seem to be jumping to the conclusion that Sarah Palmer is, beyond a doubt, a host to Judy. I'm inclined to believe that Sarah is in fact a host to the Jumping Man.

1) We see Sarah Palmer's face imposed over The Jumping Man's.

2) A long skinny nose-stalk is seen when she removes her physical face.

3) The way in which Sarah Palmer kills the trucker is inconsistent with the way The Experiment / Mother kills the NYC couple. Sarah delivers one swift bite to the throat whereas the NYC couple have their faces repeatedly slashed.

We didn't get nearly as much information about the Jumping Man as we did Judy in The Return, so I'm not entirely sure what the significance of it all is. Still, I think the gravity of the final 2 episodes have made people forget the established connections between Sarah and Jumping Man.