Incidentally (and totally unrelated to the OT) Dying Curse/Illustration is still my favorite trinket combo, due to the names of both and lore associated with the second.
Back OT: I'm not sure why listing all these mechanics from normal/heroic bosses is relevant, since LFR removes or dilutes anything that is really deadly. But since I am here, how about Instructor Razuvious? Even if they gave tanks the MC orbs like 10 man, it could potentially be a mess. Likewise with the beams on Netherspite, or the cubes on Magtheridon.