I believe that the DC Circuit Court of Appeals is unlikely to reverse it's Heller decision anytime soon. I also believe that the Supreme Court is unlikely to review a DC Circuit Court ruling in favor of Heller.
Thus, it is likely that the DC Circuit Court is going to call the shots with respect to what DC will have for gun laws.
Chicago is not part of the DC Circuit, so such decisions can provide guidance but they are not binding. Chicago will face whatever decisions their own Circuit Court makes. The home run will be if the Supreme Court agrees to hear an appeal from Chicago regarding "incorporation". Such a decision would permit the Supreme Court to dictate to the states that the right to keep and bear arms shall not be infringed by ANY government.
I was surprised when the Supreme Court agreed to hear Heller. I didn't think I would see this in my lifetime. Similarly, I didn't think I would see an "incorporation" case at the Supreme Court. I hope to be pleasantly surprised yet again. It should be obvious that Kennedy doesn't believe that our Founders intended for the states to be able to disarm people living on the frontier.
And the “unlikely” part is what this legislative deal is all about, the NRA IMO wishes to remove that doubt and leave Heller standing in DC.
Now that is risky, perhaps he DC Circuit will get “uppity” again and slap down the DC Council’s “emergency” rules that violate Scalia’s majority opinion, or they may not.