I think one thing that would make SimCity 4 complete (to an extent) is to make a tool that would port SimCity 3000 cities into SimCity 4 by automatically "reassigning" every lot on SC3K to a new SC4 standard. It would also use a method to directly bring your existing money and terrain into the new SimCity 4 plot.
This would be awesome in the fact that it would bring in a lot of old SC3K cities from the cold as well as allowing you to ultimately bring an old-school SimCity city to SC4...yeah, no kidding. :thumbsup:
For one thing, this would convince me to play SC3K and SC2K a lot more until my monitor gets fixed... :D