As this is going to be a clone, the goal is to keep the original music and sounds. The music/sounds are a bit difficult, and it will probably be one of the last features to get implemented. I have managed to reverse engineer part of how the music files work, I'm sure I'll figure them out eventually.
Now, about the AI, the barbarians and the diplomacy. I will first and foremost attempt to implement the original routines for these. I will, however, create a modding API so a custom AI could be loaded as a plugin.
My plan for the future, once I get far enough in the development, is to provide several ways of creating mods. Graphics (skins), text (language packs) mods and custom maps will not require any programming skills. New content such as custom AI, new or custom tech trees and new Civilizations will require some programming efforts but I want to provide samples (in C#, VB.NET and F#) that most people should be able to comprehend and modify.
Last but not least, I want to create the possibility to play the game on multiplayer mode.
All developments that extend or modify the game possibilities have a very, very low priority though... unless they are useful for development/debugging purposes. My first goal is to make the game fully playable. That is not far off, if I can find the time and motivation to keep working on the game. I will try my best.
For those following the development: I have just committed some new code to GitHub, allowing units to move. I am hopeful to get some features implemented over the next few weeks, working toward the possibility to play the game from start to end with a passive AI.
I will upload a new binary soon. Please, please, keep posting in this topic. It keeps me motivated. Thank you for the support!