What is this exactly and I am guessing the server is still not up.
You're not the first to ask. I think I'll prepare a brief Q&A to add to that "official" posting.
Q: What is this share map thing?A: A Minecraft share map is a singleplayer map that one person plays at a time. They have a set amount of time to play it, and when they're done, they upload the map for the next player in the queue. Rinse and repeat. That way, you have a single world with a shared creative vision without the multiplayer.
Q: So why don't you just do a multiplayer map instead?A: Every player is different. Some prefer to play solo, some can't really handle the multiplayer and some like to have a singleplayer map to complement their online servers. This is just another creative outlet.
Q: How long will I get the map for?A: Players opted for 1 week with this first rotation, but we've agreed that is too long. Each player will have it for 48 hours once we start round 2.
Q: Are there any special rules?A: Not really, other than don't be a dink. If you do, we'll just revert to a previous save and bar you from the rotation. The only big rule we ask is to please play on 'Peaceful' because we wish to preserve the built structures. Other than that, simple etiquette takes over. If you use things, try to replace some or all of it. Leave resources for the next player. Don't destroy their creations, even if they don't meet your standards.
Q: Can I be a part of this?A: Of course. Just post in this thread that you want to join, and you'll be added to the end of the queue. If you've got specific time criteria you need met, we'll try to work with you.