Id love to have a custom W101 level editor to mess around with...and a server to host them for others to play on and share theirs. Of course, you couldn't import your gear and stuff to/from the main worlds...but it would be nice to see a whole campaign set on a battleship, or a Renaissance/Illuminati theme, or a Babylonian/Sumerian world with winged bull mounts and ziggurats and such.
Members could submit textures, armatures, models, maps, scripts, quest trees, unique items, new reagents, and even graphics and stats for instance-unique gear. Understandably, we would have to waive our rights to the submissions to KI in case they get hosted/used.
I would love to see community content...wouldn't you?