I agree with stealth, I think a lot of the people voting to disable it are people who either don't want emeralds or are rich enough to afford emeralds. For the majority of Minetown enabling it but nerfing it would be a good thing.
Also, as I said in my previous post, Emeralds are only useful for decoration and trading. They aren't like diamonds which can be crafted into high-grade and useful items. If we can eliminate some trading options so emeralds are about the value of Lapis or Redstone it would be a good thing for all classes on minetown and not just those that have lots of money to spend.
Items like diamonds, diamond tools/armour, gold, Glowstone, chainmail, enchantment bottle, saddle, iron and iron tools would have to be cut from the trade options for this to happen. Then the value of emeralds would be more even, instead of all over the place. By cutting off emerald links to valued items emerald value would go down.
If I were to rank minerals in value based on rarity, usefulness and supply/demand, emeralds would be low on the list.
Diamond
Iron / Gold (same level since usefulness of iron)
Redstone (advanced circuitry, almolst level of iron but supply > demand)
Lapis (only Can be used as decoration or dye)
Emerald (If nerfed, can only be used to buy inexpensive things and decoration)
Coal (useful but supply is far more than demand)
I'm sure many more servers are thinking about this issue, so I agree that it is likely Bukkit will supply a plugin or Mojang may even edit this feature for multiplayer in vinella. (although the later option isn't as likely)
What do you all think of this proposal?