The End

The End, formerly known as the Ender, is an other-worldy dimension that was introduced to Minecraft in 1.9 Pre-Release 4. It was first mentioned by Notch.

This dimension consists of an empty sky of static, a series of barren, floating islands made completely out of White Stone with Obsidian Towers on top and is home to a large number of Endermen and the rare Enderdragon. While the Endermen will continue to exist outside this dimension, the Enderdragon will be exclusive to the The End.

Terrain and Characteristics
The End is currently depicted as a vast, barren wasteland, covered with nothing but Ender Sand. Another screenshot featured Obsidian Towers, but their release has not been confirmed. Furthermore, the dimension seems to constantly glow with a green ambient light.

Nothing else is known about The End at this time.

Travel Methods
The only way to enter The End is to obtain a number of Ender Pearls, important items that are only dropped from roaming Endermen. You would then have to mine enough Obsidian to make a Portal to the Nether, to perform the next step. While in the Nether, you need to obtain an equal number of Blaze Rods, the other crucial item that can only be dropped from Blaze.

Next, you need to convert those rods into Blaze Powder, and combine it with your Ender Pearls to create multiple Eyes of Ender. Then you'd need return to the Overworld to locate a Stronghold.

You would then have to navigate through the stronghold until you came across an Air Portal, before finally using your Eyes of Ender on the Portal to activate it.

History
In an earlier stage of development, it was known as the Sky Dimension. It had Overworld blocks instead of the current ones, and Overworld mobs spawned there.

Notch tweeted "raqreqentba", which could be decoded using ROT13, translating to "enderdragon." A Reddit user under the name of "cptqwashi" posted the idea that the new dimension accessed by the new "Crystal Block Portal" would be called the Ender, and would be home to the Endermen and Enderdragons. Notch soon gave more information and said that cptqwashi was "100% correct."


 * Responding to a fan's question, Jeb_ recently released a tweet stating that The End is the Sky Dimension, or rather The End is replacing the Sky Dimension.

Finding an Ender Portal
On 9th of October 2011, at around 9:20am (+1), during his gameplay stream, Jeb began searching for an Ender portal. This appeared to be done by throwing an Eye of Ender, which appeared to float briefly into the direction of the nearest ender portal. It is unsure as to whether an eye leads to a portal, or to a stronghold (portals are situated in strongholds) because it was implied that there was a possibility that there could not be a portal inside a stronghold. This was evident when Jeb said "I KNOW there is a portal in here because of the debug logs".

Trivia

 * Notch first mentioned The End with his comment regarding the name-change petition of the (then-unreleased) Endermen. He joked that instead of referring to them as "Farlanders," he should have changed the name of the Far Lands to The End so it would fit. But now, this dimension is an entirely seperate area in itself.
 * The Ender-Portals within Strongholds may have been how the Endermen ended up outside of their native dimension.
 * In order to enter The End, you need to have access to both the Overworld AND the Nether.
 * Unless you have an inventory mod, you shouldn't be able to access The End without participating in some combat beforehand (a number of Blaze and Endermen need to die for you to obtain their respective items).
 * The Ender Portal is one way. As of now, there's no possible way to leave the End without falling in the Void and killing yourself. It is likely that defeating the Enderdragon is a way to get back to the normal world and not losing all your items.