One thing is a given: Cable and Wolverine have some kind of past, as those claw mark scars on his face really couldn't have come from anywhere else plausibly. This does point to Cable having some association with Weapon X, since I doubt they'll reveal anything more about Wolverine's past at this point, and it places both characters in a situation where the event that caused Cable's scars could happen, whether its Cable as a guard/employee of Weapon X (like Sabretooth, a willing participant) or a fellow Weapon program who at one point was forced to fight Wolverine and lost. This could add an interesting character dynamic between the two if Cable does become an ally (having to carry around the scars on your face caused by a man now on your team).