It's inevitable as Hugh Jackman doesn't share the same mutant gene as his comic book movie counterpart, Wolverine; that one day the actor will get replaced as the adamantium-clawed bersker.
Speaking with IGN, that very fact is brought up with Hugh Jackman realizing it's a possibility.
I’m sure they had the discussion. They didn’t mention it to me, obviously! [Laughs] Look, that’s inevitable, man. Anyone who thinks they're indispensable in this business is fooling themselves. But I feel unbelievably blessed to have this part. I never thought in a million years I'd get to play him seven times. Every day I walk on the set with the claws and the hair, I thank my lucky stars. I don't take any of it for granted. To think that in a second version we'd have this cast and this director, and you guys don’t know the script, but I would say probably the best script of all of them, is pretty amazing. I think that's why I'm still here. I'm sure by the way, that it won't always be my decision to always be here. At some point, someone will close the door on me… [Laughs]
It's unknown if X-Men: Days Of Future Past will be Hugh Jackman's last film as Wolverine. There hasn't been any mention regarding an appearance in the X-Force movie, and Bryan Singer let it be known that there will be none of the original characters appearing in X-Men: Apocalypse.
The good news is that regarding a sequel to The Wolverine, Hugh Jackman did state the script would need to be right, but it's been said the actor is expected back along with director James Mangold.
"X-Men: Days of Future Past" has a May 23, 2014 release.