It is going to be click attack and click block. There is not going to be any auto attacking. I think this a good thing and should be a breath of fresh... something.
What would really be lame is if you see an arrow coming, and sidestep, and the arrow turns a corner to hit you.
Yeah I hate that in MMO's the arrow or any projectile, fireball included, should continue on the path you shot it on...and not become a homing missle... that is really lame.