I have no problem with the current level of normal dungeon difficulty. It seems about right for the average player skill level. What I would like to see them do is just mix the formula up a little more. Every dungeon is just AOE pack, AOE another pack, boss arena, repeat. Add a puzzle you have to solve or some unique way you need to beat the trash mobs, or anything to break up the monotony. Those two mobs at the start of Qitana Ravel where you have to dodge the laser walls is a good example. The mob itself isn't interesting but the room requires you to use your brain a little bit while you fight it which is nice.