Spn 5x22
Is that Sam? Lucifer? More likely Sam I would think, but then why did the light flicker? I figure he's all about to walk away all "noble" to give Dean a chance at "normal". Unless it really is Lucifer, in which case we'll probably see Lisa as the next woman in a refrigerator.
Cas & Bobby - Dead, not dead; human, not human; walking, not walking... Pfft copout.
Chuck - Was he god? How else can his disappearance be explained? I doubt all prophets just blink out of existence once they are done prophesying.
Impala - lived up to being the other main character on the show. Was sad there was no Colin Ford or Brock Kelly in those flashbacks though.
...and now that I've watched the episode I can stop avoiding twitter and the rest of the internet at large.