Most of our information comes from data collection, the majority of which was in the last 6 months (post-sunset announcement). It would be great if DBG would release the database to us, but its probably not going to happen (We've asked but no response). We have hundreds of thousands of npc placements and the world is pretty populated now. The data needs to be cleaned up, of course, though (combining multiple mobs into one roamer and setting his path). Quest scripts are being rebuilt manually from packet collections that contain the quest text and quest rewards. Item drops also have to be set manually. We obviously don't have all the crafted item permutations since we would have had to craft every item to collect them.
We also have a lot of archived fan site information and content designers who knew practically everything about the raid encounters and most other facets of the game. Thats why this reconstuction is going to take so long. Its a lot of work.
