My guess is that they will go down. Using Star Wars as a reference, re-released sets hurt the value of older sets. 6209 ( the second version of the Slave 1) was a highly sought after set reaching near $200 for sealed sets, but once the latest itteration came out, 6209 is just about what it was at retail. Granted there have been a handful of Boba's, but the newest set has a better mold and a very similar Slave 1. The same can be said about the newest falcon versus the second version of the Falcon. The minifigs have changed a bit, but again the price of 4504 is just about at retail now loose.
Granted this doesn't apply to sealed sets as much, but the value of loose sets definitely go down with respect to Star Wars for re-released sets.
Now looking at the preliminary pictures, I would suspect the catwoman and batman/joker sets that were originally released to drop in value. Two-Face has a different body, so that might not drop too much. Once we get better photos, or actual release photos, then it will probably be easier to determine whether or not they will drop.
I'm in the camp that the prices will drop due to the Star Wars comparisons.