We are talking about implementing a player-to-player Bitcoin-based economy on MinecraftCC's server... players could gain BTC by mining or placing blocks in-game as they already do, then use that BTC (or BTC they deposit) to buy blocks or items from other players. I already see many player-to-player trades go down, but also many that are unfulfilled because the right player isn't online at the right time to make the trade happen. Money would certainly facilitate a much larger amount of trading.
The only concern I have is that it might turn a bit into a "pay to win" scenario, which is definitely against everything the community stands for, but I think if only player-to-player trading was considered, it wouldn't get out of hand.
It'd be really awesome if the plugin developed for this could automatically match orders between players. No shops involved, just type "/sell cobble 1000", the server would respond with "Best price for 1000 cobble: 0.00000580", the seller responds with "/sell confirm", and the trade between the players is done. I've never played around with economies in Minecraft, so I am not sure if this is already how the bulk of economy plugins work, or if it's something never done before. It's how I would like to see it done though. Automatic order-matching just like a currency exchange.