So I was running shadow labs tonight with my guild
on the boss that mind controls-- I realized that if I hit the button for arcane missles right before he casts mind control-- I would continue to attack the boss-- and not attack members of my group for the duration of the arcane missles spell!
This comes in very usefull as I was the only DPS on the boss during that time and my group members lives as well
Dunno if it works with other bosses and other spells-- but I think any spell that takes a while while casting should work
ENJOY!