It's really hard to say how far along the total project is. Here's what I have done:
Unit placing
Unit properties
Sprite placing
Sprite properties
Unit settings
Player settings
Force settings
And what I have to do:
Trigger editor
Briefing editor
Terrain editing
Tech settings
Tech restrictions
Upgrade settings
Upgrade restrictions
Location placement
Location properties
Other details...
I'm working on the trigger editor now, and that's about halfway done. Once I have that finished, it will be pretty easy to do the mission briefing editor too. And after that, terrain editing is the only thing that will take a whole lot of time. The rest I could each do in about a day or two.