Odin's more powerful than Thanos. Odin's up there with Galactus, actually. His power level fluctuates a lot, but he recently fought Galactus and looked like he was on pretty even footing. Thor also dented the Silver Surfer's head with a headbutt in that fight.
As annoying as the leak about Thor losing his hand is, I have to admit, if they went the King Thor route and had him strap on the Destroyer's hand in its place, that would be f***ing awesome.