Recently DC has asked Brian Bolland if he was going to draw a sequel to Batman: The Killing Joke. The request came from DC Comics to Brian at the KomMissia Comic Convention in Russia. And since Brian Azzarello is working with Frank Miller on The Dark Knight lll: The Master Race it seemed like it might be possible for both Bolland and Azzarello to take on. Of course Bolland commented on the fact that he declined to do a sequel due to his age and the pain he would endure from taking his time to create another comic let alone the time it would have taken him to complete it would have been too long in his opinion.
So with now all of our hopes destroyed and dropped in a vat of acid, it would seem like this is the killing joke. Brian Bolland did say that the general impression that he got from DC is that even with Azzarello working hard on DK3 it did not seem apparent to him that they would want to look for a new artist to pick up the iconic Batman: The Killing Joke sequel. Of course there are teasers out there and easter eggs to Killing Joke from Jared Leto in his upcoming Suicide Squad movie.