WASD is great if you're left handed, but that's only 2% of the world's population, so I should think a unanimous vote would automatically go to the arrow keys.
It just doesn't feel right crossing my dominant arm over to get to WASD when I could just comfortably use the arrow keys. (I only play games with my left hand if my right hand is already in use)
Personally I use WASD a lot, especially if i need to use the spacebar, for say, attacking, I can get a thumb on it and my fingers have my movement. The arrows are a pain for me, even though I am right handed,
if i have to use the mouse and keyboard at the same time, then i use WASD. but if i only need to use the keyboard, then arrow keys. i dont know why, but it just makes me feel more relaxed and comfortable :3