a store for materials
I'm sure many know the frustration of needing a particular piece of material for gear. The slow round of assailants often means weeks between appearances of the assailant that you need material from. My idea is simply a store.
No, I don't think trading or gifting gear is a good idea as much as alts would benefit greatly. However, I think a store where specific material can be purchased using a particular currency would be awesome. This currency would be obtained by sacrificing a piece of material you already have. The trading could be anywhere from 1 for 1 to 10 for 1. This would allow me to get rid of materials I have excess of and get materials I need without having to wait for the right assailant to show up.
This same principle can also be applied to runes (since they already found a way to rid excess inventories of gems)