Cyber

Here's another interesting villain who could cameo in the final Wolverine flick. Basically impervious to any harm, Cyber is almost completely covered in adamantium. Only his face can be injured (which is a bit weird "“ and maybe it should be left out in a potential movie). Not even Wolverine's claws can scratch him.

Furthermore, this villain can track its enemies, possessing powerful psionic abilities. As we saw from the set-photos, Wolverine, Professor X and X-23 are on the run. Could it be Cyber the one who always finds them?

Who is to say that Sinister's experiments with adamantium ended with Wolverine? For a secondary villain, Cyber would be great.