I wouldn't mind optional Extreme Dungeons. I wouldn't mind if there were 8-man dungeons. I wouldn't even mind harder dungeons (thought outside of ilv restrictions or mechanical gimmicks, I don't know how you'll up the difficulty. And once a mechanic is known and people have done it enough, the difficulty of the dungeon/trial/raid drops considerably).

What I do mind is a 24-man anything that cannot be DF'd. If anything that should never happen, it should be that.