No more certain than X-Men Origins: Magneto
was. We'll see...
Not ageing, Jackman can continue to play Logan until he's fed up (or looking too old).
Before The Wolverine
came out, I thought they might end up retaining his healing factor but still cause him to age normally. And they still could somehow, by having him seriously wounded by a gamma beam, or friend by a sentinel's rays or something. We'll see...