The main new feature being added in My Colony v0.70.0 is for premium users, and is the new concept of Regions. Coming soon, when you create a new game (online or off), you will be asked if you want to start a single city, or a region.
If you have ever played Sim City 4, then you kind of know the idea behind regions. Basically how it works, when you start a new region, you get a blank map that looks like a regular map, but instead of placing buildings, you can either place a Small City or a Medium City. You then start a new map using that size of city. When you go back to the region, a tiny little picture of your map is sitting in the plot of land you selected.
The idea is that the entire region shares a common resource, electricity, atmosphere, and technology pool. Also, the region declares independence as a whole. The region is 50x50 in size, so in theory you could have 2,500 small sized maps in a single region, although that would be crazy.
Either way, the support is somewhat experimental right now. It's been on the web version for a couple of days, but I do not suggest starting a region yet until the official release of 0.70.0, as you will likely have to start all over again from scratch. Many things have yet to be implemented, and that will happen in the coming days. I just wanted to let everyone know what it was, so nobody starts a new region yet expecting it to work properly!
If the regions turn out to be popular, I might also add moons and asteroids that are part of the same region system, but don't necessarily share the same resources, at least not electricity and atmosphere.
Anyway, somebody suggested something similar in the forums the other day, and I always loved the region aspect of Sim City 4, so that is sort of my guide here in implementing this, although SC4 did not share money between cities, I think it would be need to do so here.