We actually don't really need it. We plan out ideas very carefully, such as TB did in his combat mod. Google docs are a great way to do so. Once you have a solid idea/plan, you can post it here and maybe work on other stuff. In the meantime, the others can review your ideas and you can sleep over it and maybe change your mind. It worked out for over 7000 SVN versions now

Just make sure that you don't post like:
Building A: Changes. What do you think?
You can add a bunch of these (say A-C) and let us think about it. While we do so, you can work on D-E for example. If your plans are reasonable and well thought out, there shouldn't be too many rejections (when you got familiar with the mod, as Hydro said). So if you post 50 buildings at once, probably 5 needs further discussion, but 45 are already approved. Just be patient

Starting with audio files adding is a great idea, you don't need any approvement for it and can do ass many as you want without wating for the feedback of us slowpokes

And it would be a big help!
What also needed to be done is updating the building list we have for the electricity mod for example... But it's a very boring job, so I'd understand if you don't really want to do that