Well, AoE physical attacks like BD skills and stuff like that can be evaded, but what I said was you cannot evade AoE magic spells, as in spells that have you target an area on the ground, including the Bard and Hunter DoT's. I don't know what mage spells look like since I've never played mage, but I assume they have aoe spells like that as well.
As for boss AoE's, the same applies. When its a physical attack skill then, again, sure you can evade that. But AoE spells (which usually carry a debuff with them) cannot be evaded.
Notice I make a distinction between skills and spells.