Nothing really big, not game changing, and im not sure if it belongs here (not really sure if its an exploit) but it turns out that thorns(having a spell power coefficient) does a good amount of damage to mobs at low levels.
Example: Today i was leveling a character (hunter, level 10) and I had a druid friend(lvl 80) put thorns/mark of the wild on me. I tagged a mob, and it hit me, doing 82 damage to the mob (the mob having 100 hp) i was able to 2-shot it, and get full exp.
Not sure how far this will work, due to the fact at level 80 it hits for about 200 or so. but good for low levels killing a few things quickly.
once again, im pretty sure this isnt an "exploit" but im not really sure where to put it :P