Now, that's more like it. Actual initiative.
Just wonder if there is any particular reason why this would have to be the guild warehouse and not the warehouses of the individual player?
The reason I ask is that implies this will be a voluntary thing, meaning that anyone who chooses to hold on to their goldbars are free to do so and still spend them on the Auction House, keeping their gold in circulation.
Still, I like the guild approaches here, although the various guilds will have to come to internal agreements about what they will do with the OPs or what the GL should do with the gold before people start donating, depending on the choice you land on.
And then there's the final snag, made even greater with the server merge: only 60 guilds will qualify for this...30 on either faction. Before the initial merge, this would have worked wonders, now the members from about 180 guilds that ranked in the top 30s before the merges will not be able to do this after next week's merge...meaning you could have reached the majority of the players for this a couple of weeks ago, while you will now reach less than half. 
Which is why I think considering goldbars in individual warehouses and toons for this idea rather than the guild warehouses might be a good idea...but if the GWH option is gone for, that means the change for OPs option has to be ditched, as that would give the top 30 of either faction massive advantages over those who cannot rank.
And then there's the awkward little fact that goldbars are currently untradable and cannot be put into the GWH. Yet.
Good initiative, though. I'd vote for full removal from individual warehouses and toons overall, but given the choices above, I'd say to remove from the economy altogether. Remember, only the top 30 on either faction can use the GWH.