I really do enjoy the idea of a trailer! This is thinking quite far ahead tho, a lot of the building seems to be good at a steady pace, but considering the fact that there are new and possibly other cities that have been introduced in The Legend of Korra, may inspire the builders to build those as well, or update some of the builds to best fit the plot! My point would be that if this would be done it could take quite some time! (I made this too long, sorry everyone!) :/