Sky dimension

The Sky Dimension (otherwise known as the Skylands, Floating Island Dimension, Dream World, Aether or Heaven) is a work in progress by Notch. It "performs well, [but] looks ugly". It is now a confirmed update but the release date is not known.

In a live webcast on the Swedish gaming site feber.se Notch revealed that the Sky Dimension would "probably be a dream world" and that when "you go to bed there is a certain chance that you get dragged into the dream world instead. Then you will be able to do it on purpose later on."

History
The Sky Dimension was first announced after Notch played Spleef against a man with the twitter account named "Evil_Notch" (video is on twitter). It was probably made to be like a "heaven," because the nether was considered to be and act like a hell declared by the Evil Mojang team. The sky dimension was not completely confirmed until Notch released an update via Twitter stating: "And because PC Gamer made such a big deal of the sky dimension, I guess I'll have to finish it. Consider it confirmed."

The Mod-Enabled Version
Notch left data in for an early prototype of the sky dimension in Beta 1.6 and 1.7. Using various mods it is possible to access this currently unfinished version of the Sky Dimension.

In this version of the sky dimension it is always midday and it does not rain or snow (though cloud cover does appear as if it were raining). Sugar cane cannot be found normally, and although uncommon, it is possible to find Redstone, Lapis Lazuli, and more rarely Diamond. Like the normal world, you can also find Dungeons. Iron, Coal, and Gold are commonly found. Iron and Gold are found in larger patches than in the overworld (up to one vein of 30 iron). The only mobs that currently spawn in the sky dimension are chickens and very rarely cows and pigs. Below the islands of the sky dimension is nothing but the void and a layer of clouds.

Trivia
is a huge rock filled with sky, the former is a huge sky filled with rock.
 * If you select a map while in the unfinished version of the Sky Dimension, your game will display the saving chunks screen and crash, because the current implementation of maps can’t handle exposed sections of the void.
 * Maps work in the Sky Dimension via SMP.
 * The Sky Dimension is a literal inversion of The Nether, whereas the latter

Videos

 * Notch's Sky Dimension in Minecraft Beta 1.6.4
 * Notch's Sky Dimension in Minecraft Beta 1.6.4 - Exploring with Hot Air Balloons!