If you go by the interviews (more specifically Anthony Hopkins himself), Odin is dead.
You're referring to that
MTV interview right? The thing is, you kind of have to watch the actual video since sites didn't really write in their articles exactly what he says. They have him quoted as saying along the lines of "He's dead. I've done two, that's enough."
What he really says in the actual video (emphasis by me): "
Maybe, maybe Odin dies, I don't know. I've done two, that's enough."
(note: and he says that in kind of a light-hearted manner, so I wouldn't necessarily take it that he wants out of the franchise yet - though if he did, I think they could work around it)
Side note: even the director seems, from what I can tell actually watching it, misquoted on sites in regards to that that interview - what they credit to him saying about Odin I think is actually more about Loki and about their decision to kill him (Loki) off and then have that big reveal at the end.
Right now, I would take Feige as the "Word of God" on the topic which is simply "We have very good ideas whether the All-Father is with us or not." and he's left it at that... which tells me his fate has been left ambiguous very much on purpose.
