McClane Going Up Against Another Gruber?

So it looks like the villain in "Die Hard 5" may be another Gruber. Rumors are scatering, saying that John McClane maybe be taking on another Brother, or maybe a Sister, it might even be Son Of Gruber.............or Daughter in the upcoming "Die Hard" sequel, which is said to be filming sometime this year as the script has been confirmed, by Bruce Willis, to be finished.

Possible title: "Die Hard Gruber Number 3"