Recently, Kikidas reminded me of a popular thought in how to make guilds stronger: a guild house/stronghold of some kind, with various customizable decorations from trophies from kills and accomplishments.
The problem with guild housing is that the room is communal property. A brand new guild member walks into a room that has everything populated or empty, just like someone who has been there the whole time. Just like guild banks, you can't have everyone editing a room, right? I mean, I don't let my wife edit my office desk arrangement (the mess is just so, thanks). Plus, you can't take a guild house with you: if your guild goes south, you have to leave the house behind.
But why don't we make guild success personal, like the new Achievement system is?