Excellent idea. This is really lacking from the new prediction league, and is the only reason I prefer the old one - overall leaderboards.
I would be really interested in seeing the following leaderboards as well (not just because I would be much higher in those than in the one listed ;) ):
-Overall average prediction accuracy.
-Overall total bet winnings.
I can make an overall total bet winnings, but that will have to wait till tomorow, as I don't have access to my program for the rest of tonight.