In the latest episode of supernatural Season 8, Episode 2 - What's Up, Tiger Mommy?, who do we see bidding for Mjolnir? I strongly suspect that it was Loki, one of the few I can think of that would 'remember' the weapon. Am I right? We haven't seen Loki already in Supernatural, have we?
According to the supernatural wiki, the being in question is Vili.
'In Norse mythology, Vili and Vé are the brothers of Óðinn (often Anglicized Odin), sons of Bestla, daughter of Bölþorn, and Borr, son of Búri.'
All I can find on him is that he gave, according to norse legend, the first man and woman their intelligence.
The "old man" we see bidding for Mjolnir in that episode was indeed intended to be Vili as shown in the end credits. He is one of Odin's brothers which explains the previous connection to the hammer. As mentioned, there is also lore of Vili, Ve, and Odin slaying a Frost Giant together. This explains why he has the finger.
Remember how Gabriel was undercover or hiding from all the gods, who thought he was loki but he wasn't? He had a finger of a ice giant which relates to Loki.
Because of this I'm sure the bidder is loki; he always wanted the hammer (in norse mythology at least) he has access to ice giants even in the comic (Marvel?) he helps thor to battle the ice giant (I forget the name he called him in the show).
I'm sure of it. Everything falls in place to easy and with that season being all about gods well, it seems to fit nicely.