There's been plenty of scuttlebutt regarding Wolverine 3 (which still has an impressive amount of secrecy about it), and much of it concerns which unfortunate soul(s) Hugh Jackman's adamantium-clawed mutant will have it out for this time round.
We got a hint at that answer in X-Men: Apocalypse's post-credits scene - which had the name Essex Corp. embroidered on a briefcase, a reference to Nathaniel Essex aka Mister Sinister - and on the DVD commentary for the film (via Cinema Blend) director Bryan Singer confirmed that the baddie will indeed be butting heads with Logan next year.
When you put this information together with previous rumours and assumptions, Wolverine 3 starts to make a little more sense. Mister Sinister has been known to tinker with mutant genetics, and given that there's already been a few indicators that X-23 - a female clone of Wolverine - will be in the film, it's not that big of a leap to theorise that Sinister had a hand in her creation.
As for who will be playing Sinister, Richard E. Grant seems a likely candidate; His character was described as a "villainous, mad scientist type" when news of his casting broke, and that fits Sinister down to a tee. Director James Mangold has promised that the first trailer from Wolverine 3 will be online soon, and the footage will undoubtedly yield more questions and hopefully a few answers too.
Directed by James Mangold and starring Hugh Jackman, Patrick Stewart, and Boyd Holbrook, Richard E. Grant, and Elizabeth Rodriguez, Wolverine 3 will be released in cinemas on March 3, 2017.