There actually is! Currently it's whitlisted/invite only. It's ran by Dinnerbone (OMG CREATOR OF BUKKIT AND ADMIN ON MMOC) and me, Dinnerbone is really busy working on Bukkit at the moment so it's been left in my hands for now.
We have a stable playerbase of 10ish (always nice except Miceiken) people. Before 1.8 we had three different maps, Creative, Survival and Hardcore.
Creative is basically just a map where everyone has the /give command and with basic protection.
Survival is exactly as it says, with basic area protection etc.
Hardcore is something Dinnerbone cooked up, it's a random map (converted from an image (
last months map), with lower spawnrates on pretty much everything. You can make "teams". These teams have a "base". If another team finds your base, they can loot it, destroy it.. whatever!
Currently we are running on a temporary 1.8.1 map as we wait for 1.9. After the Minecraft updates calmed down a bit we'll probably do the above again, but improved.
We really want to go public, but are kind of low on diskspace. The server rarely/never lags as it's on a dedicated curse sponsored box that only runs
http://cursecraft.com (WIP) and the Minecraft Server itself.
You can join us on
IRC, but seeing it's currently invite only I'm not sure whether there'll be a chance for you to actually play.