Can't stand the arrow keys! Gotta move my keyboard all diagonal, because of my small pull-out-keybord-panel-thingy. I do have a lefty buddy that has his mouse on the left and everything. He uses the arrow keys.
WASD rocks. I love how you can use it for your left hand, mouse on the right, and hit all the hotkeys without having to move your arm, just your fingers.
I use neither, I have a MERC Gaming keyboard and it has a gamepad typeish thing on the left for gaming. The drivers come with over 200games to change the layout for it Its cool.