In general, Dalaran Arena is a pretty cool arena (coming from a mage who usually suffers with all the los issues), but the boxes are pretty much calling melee "Come abuse me".
I have an idea how you can make this arena fun for all classes, dps casters and melee.
The solution is:
Remove the boxes from the sides and place 1 pile of boxes that is constant in the center.
Instead of the 2 box piles in the sides, you can put the waterfall on timer effect there.
This would keep all the features in place, but would prevent box abuse.
What do you guys think?