I remember a post a long time ago asking about using a gamepad with GuildWars. GuildWars doesn't seem to support mapping to external controllers, so you will need 3rd party mapping software to get this to work. I am using a Logitech DualAction Rumplepad 2, which comes with a WingMan Profile software package. It works by making the control pad buttons map to certain keys on the keyboard. You can save the keymaps on a game to game basis in profiles. I've done some experiementing, and I've come up with a control scheme that seems to work fairly well. I can't really reccomend using a controller if you usually type to communicate, but if you use TeamSpeak or some other such program, this works beautifully:
Keyboard Setup
Forward: WBack: S
Strafe left: A
Strafe Right: D
Turn Left: Q
Turn Right: E
Zoom In: I
Zoom Out: K
Skills 1-8: 1-8
Target Next Foe: Tab
Target Next Ally: B
Target Self: F
Target Next Item: ;
Perform Action: Space
I have included the saved profile for anyone interested.