Anyone who raids can see that this is going to continue to be an enormous problem as new dungeons start to come out. I have a simple solution to this: add a guaranteed "varying" quantity of 1-3 Black Lotus drop to the last boss of a raid instance, sort of how the mana potions in the DM Tribute chest work.
Ragnaros and Onyxia would be the only bosses to drop them at the start, the 20 man raids may be another candidate for this as well, seeing as it would also add an incentive for people to continue to raid these instances long after they are deep into AQ/Naxx.
I don't think this would have a drastic effect on the server economy, seeing as these are consumable items and are used weekly by the players dedicated to progression on raid content. I am curious to see what everyone thinks, flame away.