Maybe they will find a new leader that touts 'Change'! They will all have a unified healthcare system and Overlord's will tax the zerglings to give stimulus back to the collective.
And one day we'll look back and say, "I remember a time when you could get
two zerglings for 50 minerals, not just one."
I think reverting Kerrigan to "human" form didn't erase her memories. She also had powerful psionic abilities before her transformation; there's no cause to think that she won't possess at least the same pre-transformation levels of power in the next chapter. If that's the case, it's not unreasonable to think that she can still influence the will of the Zerg collective--while free of the external corrupting force Tassadar mentioned in the Prophecy missions. That is where I'm guessing--and hoping--the story will go in Heart of the Swarm.
Even if she is biologically 100% human, that doesn't mean her mind isn't still part Zerg.
It's worth noting that Kerrigan wasn't exactly a saint before she was transformed by the Zerg and her (justified) anger at being betrayed may very well have shaped her character as the Queen of Blades. The idea that a character's most natural and/or intense emotion at the moment of gaining tremendous power will set the trend for that person's character for the duration that they posses the power is fairly common in sci-fi or fantasy narratives (including the story of Arthas and the Lich King).
Put another way: Humans hold back any number of violent impulses in a given day because we understand there will be repercussions if we act on said impulses. If a human is suddenly freed from those repercussions, what is the likely outcome? Indulging in those impulses. Her actions as the Queen of Blades may not have been as contrary to Sarah Kerrigan's character as some might like to believe.
Kerrigan may have been a "good guy" in that she defended others from the Zerg thread prior to her transformation. That doesn't mean she was a person of good
character. There are plenty of people with wicked hearts who obey the law. Some ("some" does not equal "all" or even "most") even help enforce it.
So don't assume Kerrigan's transformation will be as simple as "from demon to angel" or "Where am I? And what do you mean it's been 4 years since Tarsonis?" Such oversimplification would be lazy writing and a missed opportunity for legitimate sci-fi-style exploration of what makes humans human.
