When the game gets boring, indulge in the metagame. Or the metametagame. I think that's what the Lounge subforum is for, right?
Alternatively (or concurrently?) start up a few new cities on other servers with wildly differing goals in mind. I personally strained myself on the slog that is the Orcs chapter* so I went to build a new city on Felyndral with some minor prodding with the idea of "what if I never built the barracks to begin with?" and "Maybe I should play as a human".
I've had I'm having some fun with that one. I'm pretty sure there's other challenges out there, such as "what if I built my city as a ring?" or "what if I had myself only two manufactories of each type and maxed out on armories, floaty lizard pits, and smart and stinky green man training zones?". Or go total hardcore mode and try the Education Is For Frail Fingerwigglers Route (No Magic Academy) and see how long you can tough it out.
And then come back to the forums and make a serious petition to add Extreme American Orc Football and push it to the point where the game might need to be renamed Orcinar, which is a Fantasy Football type interactive betting system with a thin citybuilder layer plated on top of it.
* The slog is entirely my fault, and is on purpose. I fear the Woodelves.