Sky dimension

The Sky Dimension (otherwise known as the Floating Island Dimension) is a work in progress by Notch. It "performs well, [but] looks ugly". It is now a confirmed update.

It is still unknown how one would travel to the Sky Dimension, but the methods most likely to be implemented will either be by creating a portal, much like the method of travel to reach the Nether, or simply climbing there with ladders, stairs, etc. Also unknown is whether the Sky Dimension will be a part of the normal world, or whether it will be separate, like the Nether. If it is separate, falling will most likely be handled in a similar way to when a player falls into the Void.

The Sky Dimension was first announced after Notch played spleef against @Evil_Notch (video is on twitter). It was probably made to be like a "heaven", since the "Evil Mojang" team declared to Nether to be "hell".