Cheers!
Chip: For Quake files it currently is not too interesting. The structure is exposed by their download locations, ie where they serve the actual download from. Newer files do not have that anymore.

But we still get nice metadata down from the download pages and more.
reckless: Got a decent upstream (>1MB/s)? Would be best if you could join the IRC channel, #fireplanet on Efnet.
I estimate the full thing to be at ~4 Terabytes. So far we got almost 500GB down. The big files are still ahead. Worst case would be a total of 7TB.