Thanks for all the feedback and its nice to know that it should be implemented in the future.
It does seem some people are miss-understanding what I mean by a guild storage, and what a merchant npc is...
I mean both are great ideas but both perform totally different functions.
NPC Merchant sells any items you give to it, at whatever your set price is. Where-as the guild storage would simply be a place to store items that all of your guild has access too.
I agree that the guild leader should be able to set an access level so only certain groups of players can get access to the stored items however. And if a new member wants an item, they will need to ask for it from an officer and not just pinch all the items themselves.
Its a very real threat that if the guild storage was open to just everyone in the guild, a new member could just come along, ransack the place and then quit the guild never to be seen again.
Anyway, nice to know its being considered by the dev's