Too little, too late when it comes to Zaraki. The one massive chance he had was with fighting that one Espada, but instead Kubo just made him use two hands. Since then, it's simply a case of who really cares with him.
Given how horrible most releases are for even captains, I cannot even begin to imagine that this will be awesome. I mean, Zaraki is the most over hyped when it comes to a release, and nothing Kubo makes up can live up to it. At this point it would have been smarter to simply never let him know the name of his sword.
Or at the least, show him learning the name of his sword at the very end of the series and leave us wondering what could be. Which actually could happen, knowing Kubo; he could cut away for who knows how many chapters and just kill any and all interest.
Oh, and if this kill rock doesn't explode into the ToQger team then I will be so let down. Them or trains. Trains EVERYWHERE.