As I've learned today, the "Top Users" lists that were previously shown in every forum space are no more. It is going to be replaced by Jive Leader Boards, which is part of advanced gamification that has been enabled a few days ago. You can see the new Leader Boards in action in the Middleware forum or even here at Oracle Community Ideas looking at "Individual Leaders."
Ironically, the new reward and recognition system relies on the use of badges to compute points, and the Leader Boards start counting from the day advanced gamification was turned on. The system will essentially reset and start from scratch. Past contribution efforts to make it into the Top Users lists and possibly years of advance is going to be lost. I seriously doubt that many previous top forum contributors would be very keen to sprint the extra miles necessary to start building their reputation again.
I don't know how it can possibly be done, but I suggest to restore the recognition and efforts of previous top users.