If I've understood the system, you can all create weapons by adding them into the open data files.
I haven't tried yet, but it seems to be the reason the Carceri engine uses/will use them - they're simple to add things to.
Now, regarding all the terrible things said about Diablo [1] :) :
Diablo was and is an amazing blend of game and ATMOSPHERE - I don't want *all* my games to be skill- and action-based, Diablo's a horror-gothic themed game of very high quality, and is as capturing as any book.
Diablo 2, although I like it very very much, is *nothing* like that. There's been so much effort put into the 3Dish graphics and multiplayer balance, that the smooth, dark, painting-like graphics that are in Diablo are lost almost completely. Sure you can see what the guy's wearing, and sure it might be worth using, but it also might look rather ludicrous, taking away alot of feel.