The comic plot of Ragnarok seems to be the direction that the Thor franchise is headed in with actors Chris Hemsworth and Tom Hiddleston dropping hints about the story being played out. But where does that leave Odin?
Odin's fate was left ambiguous after the events of The Dark World where Thor left to go to Earth and Loki was posing as his father on the throne. It could be that Odin was slain by Loki or he could be locked away, either way he could be giving his powers to Thor to help with the events of Ragnarok.
In the comics, Thor assumed his father's place and claimed the Odinpower, but it departed from Thor just as Ragnarok finally came to Asgard. Assuming a child's form, the Odinpower helped lead Thor on a journey to realize how Those Who Sit Above In Shadow had manipulated Asgard for ages; although Thor could not halt Ragnarok, he prevented Those Who Sit Above in Shadows from exploiting them further.
Thor eventually reclaimed the Odinpower and revived all the Asgardians who had fell in Ragnarok, but Odin himself remained deceased. When Thor took an Odinsleep, he went upon a spiritual journey to a land of the dead where he found that Odin was locked in eternal combat with Surtur. Although Thor had the power to release his father, Odin preferred to remain where he was, ensuring that Surtur would never threaten his people.
This sounds like an interesting direction to go as it would allow Anthony Hopkins to return to the franchise but not require too much of him, almost like a cameo role. It also would give Thor powers to fight the Ragnarok apocalypse and find how to save his father.