sobrenatural discussion?

Hi guys, I was wondering if you guys had any opinions on something I've been wondering about. This might have been a long time ago, but if you remember back to I think the season 8 opening episode, Sam leaves Amelia and sneaks out quietly. If you recall, there is a figure in the shadows watching him as he drives off. Any ideas on who it could have been? I've eliminated a few people myself.

-Dean: he did not know about Amelia until Sam brought her up, and he was at the cabine too so he can't be in two places at once
-Bobby: he wasn't alive
-Castiel? I'm not sure about him, was he saved yet?

And do you think that the figure is evil or good?