This is the moment some of you have been waiting for: multiple worlds are now available! Read on for a description of each one, some useful notes, and something orange. Click on any images for a bigger version!
This is the main world, which has been running for over two years and remains our main playground. It is now named Laurasia. The survival difficulty level is set to normal, as before. The old areas have been created by Minecraft's default generator, while all post-1.7 areas are set to large biomes.
Looking for an extra challenge, or something different? Visit Gondwana! This is an amplified world, meaning that most biomes can reach up to the sky limit. This creates several gravity-defying structures just begging to be climbed. To increase the challenge, this new world's difficulty level is permanently set to hard. Zombies can break down wooden doors and you can starve to death, among other perils. Adventurers beware!
Back by popular request, this is a large, player-made survival island. Featuring a large mountain, a volcano and several very tall trees, this small world is a nice building ground for those looking for something different than Minecraft's standard lands. Some players might remember seeing it as a temporary creative world during a previous server maintenance. It's now permanently back as a survival site, on normal difficulty.
General notes about multiple worlds
Your inventory carries over all worlds, including the content of EnderChests. Those looking to start anew are free to step over to their new destinations carrying nothing; those who would rather start with some handy tools are likely free to do so. Nether portals will only work on the main world, Laurasia - building them in other worlds won't allow you to go anywhere. Head to the center of the new worlds for a teleportation pad bringing you back to Laurasia. Note that both worlds also have a set barrier that you can't cross: what you can see the map is the full extent of each world. To keep the difficulty level high, keepInventory will not be toggled in the alternate worlds, even on Events Nights.
The maps for these new worlds is generating at the time I'm posting this information and will be fully available soon enough.
To travel between hubs, you have to access the Laurasia TransHub. Located in Central right next to Grand Central Station and the Nether portal, this area has teleportation pads leading to the spawn points of each world. To return to this location, use the nearby exit pad found near the center of each world.
Large mesa biome
Mesa! Mesa? Mesa?! Mesa! Mesa...
You wanted a mesa biome! You looked hard to discover one! Others with the same goal helped you! But no one could locate such a special place to this day...
Worry not! To give everyone a chance to walk on that orange soil, a large mesa biome has been transplanted on the main world, Laurasia. This area is large enough to allow the development of several towns and construction projects, along with looting of rarer blocks.
Its location will be very obvious on the map as soon as it finishes updating. Overworld and Nether rails will be built soon to allow quick access to this new biome.
Go forth, fearless explorers, and discover all these new places!!