It's an idea that needs to be installed in my opinion. If Guildies don't like the idea they don’t have to contribute. Here's is my take on what it should be:
-We will send all spare money & blue/purple items to it. This way we are making an attempt to make contact with all other guild members as opposed to just people your level.
-We will also send rare trade items to it.
-Made in an officers name. It will be his/her responsibility to continually list all that's in the bank via a forum thread or via WoW Rankings. He will then make sure the equipment his given fairly.
-If two people want the same item it is either 'first come first served' or a /roll in-game.
-If the officer leaves the guild they will close the character name and leave the space for the next person to fill it.
-Inappropriate behavior we have no control over will be reported to the Games Master.