To add to all of the wild guess work I'm also thinking we haven't seen or heard the last from Boulder.
The radiation left behind surely must have some kind of ill or positive effect on the little ones and I'm sure they didn't all die, at least not right away. I believe people/animals have been known to survive nuclear attacks although they obviously aren't in the center of the blast radius. Usually these survivors die off due to the radiation right?
I somehow get a really really really strange feeling that all survivors (including what's left of
the mallers) may have to team up to fight a ridiculous onslaught of Zombies. I'm thinking Lord of the Rings battle for Helms Deep here ... I don't know where I think it's going to go down but I just have a feeling this story sooner or later will be all about surviving the Zombies. There is so much left in the whole Ink story and the creation of the little ones as well ...