There are about 37 specialized buildings ranging from wheat farms to archery ranges, and that doesn't include the houses which Villagers will reside in. Then there is a road system used for moving about, a minecart subway system, and an underground water network to name a few. I still need to figure out how many Villager houses there should be, and this depends on what the estimated population of Villagers could be expected to "run" the city.
If you would like to see the plans as they are now, you may check the project's website at http://ultimatecity.wikia.com.
Still left for me is to decide on a spot on the project's server where the building will take place, as well as come up with a rough idea of the city's overall shape. This will be important for laying out the path of the subway system, amongst other things. The server's spawn point is located on a huge continent, and there is an impressive, relatively flat area to the west which would hold the city nicely.
I am thinking that if I do get the chance to record, and I can get on the Ultimate City's server, it'll be a different series than my current one.
My desire for the city, once it's completed, is for people on other servers to copy it and use it on their servers as well. Maybe they'll make their own version of the city, fitting to their ideas of an Ultimate City. Or perhaps they'll do a literal file copying so they have the city as it's built. The city is intended to be a place where you can be secure and well-stocked, making for an awesome stronghold to dominate on a PvP server.