"Conurbations" might be too easily mistaken for other words in several North American English dialects, I suspect. So, "megapolii" it will have to remain for the time being.

Such tomes in Mandarin dialect as predict our downfall...well, they've been written from time to time for a good while now, or so the suspicion runs. Some of those hegemons seem to have twigged to the idea of adopting more wholesale political reforms to go with their economic changes, though, and I wish those particular hegemons well with that project. Its success might bode well for our shared future as a species.