I might be wrong here but I would seriously doubt it, its papers being papers.
I know he is one of your own and without him Sunderland would of been dead and buried without him, but a lot of people have forgotten that before this season noone in the prem wanted him the 2 interested parties were Derby and Sunderland. The likelyhood is he wouldn't be at Sunderland if the Nugent deal hadn't of fallen through.
Ironically its sunderland suffering from injury and being poorly defensively that has helped KJ reputation no end this season. He is without doubt one of the best in the prem with balls lumped upto him and his back to goal. A couple games he has been unplayable, but in not as many games as he should be. KJ is still relatively inexperienced as a CF and it shows on occasions and it will be interesting to see him playing with a decent midfield, certainly a fit KR, CE and AR would be a massive difference to sunderalnd. He will need to change his game a bit and learn to play differently and I am sure he will. At the moment we haven't seen him because he hasn't had a chance to find himself space in and around the penalty area, he tends to be caught on his heels the couple of times he had a chance to do this so far, he looks a little lost when other players are attacking with the ball, he doesnt take a risk and run across the near post, he has a tendancy to get himself in the middle of the box and wait for the ball to be pumped into him. He also lacks a little composure in one to ones but this agian is down to lack of experience. A better partner up fron would also help him greatly. All these things will come if he is willing to learn and has the midfield around him to create the space and chances, then he will be a hell of a player and will deserve to play for a top 4 side.
It will be interesting to see what happens if we are relegated as I said before I seriously doubt he has a clause in his contract, but rather will the club cash in on him is the more likely debate.