Wow! Now why can finally have actual towns and city's! Nice 
Still, I'm not very hyped for this, mainly because I don't want to, it could easily end up a a disappointment 
I'm pretty sure you misunderstood. The towns you create appear in adventure mode and not on your normal play planets.
But, Planet editor and fire breathing?! Looks like Maxis pulled through for us!
Don't see anything about a planet editor. But it says you can personalize planets with the adventure editor, so you probably could use it to make towns and cities. They just wouldn't produce spice, like normal cities.
And I don't think there's an "Adventure Mode". The adventure scenarios are probably placed on normal play planets, though you would have to get out of the ship to actually play the adventure.