I agree...even though we have no endgame dungeons on Beta and we have absolutely no information so far.
I believe Vanilla dungeons were all a matter of "not over pulling" and "do not mess up" and "dont sleep healer".
I imagine it as a residentsleeper emote while doing the dungeon...and while you are in a sleepy state...you mess up and die.
Its the only way to fail in Classic IMO
I could be completely wrong
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A lot of assumptions beeing thrown around. I choose to wait and see for the opinions of Pros.
Those threads have pitiful data being thrown around :S