Minecraft Snapshot 14w17a! 

This includes:
World Customization
World Borders
New Endermite Model

World Customization

World customization maybe hard at first, but when you know what to do, it gets easy!

Here is a glitchy preset I made, where it's kind of superflat, without trees or anything, but there is stone dirt etc. but the grass is level 256 so you hve to dig down to place blocks! I call it "Glitchyflat"

Preset: {"coordinateScale":6000.0,"heightScale":6000.0,"lowerLimitScale":5000.0,"upperLimitScale":5000.0,"depthNoiseScaleX":2000.0,"depthNoiseScaleZ":2000.0,"depthNoiseScaleExponent":20.0,"mainNoiseScaleX":5000.0,"mainNoiseScaleY":5000.0,"mainNoiseScaleZ":5000.0,"baseSize":25.0,"stretchY":50.0,"biomeDepthWeight":20.0,"biomeDepthOffset":20.0,"biomeScaleWeight":20.0,"biomeScaleOffset":20.0,"seaLevel":63,"useCaves":true,"useDungeons":true,"dungeonChance":8,"useStrongholds":true,"useVillages":true,"useMineShafts":true,"useTemples":true,"useRavines":true,"useWaterLakes":true,"waterLakeChance":4,"useLavaLakes":true,"lavaLakeChance":80,"useLavaOceans":false,"fixedBiome":-1,"biomeSize":4,"riverSize":4,"dirtSize":33,"dirtCount":10,"dirtMinHeight":0,"dirtMaxHeight":256,"gravelSize":33,"gravelCount":8,"gravelMinHeight":0,"gravelMaxHeight":256,"graniteSize":33,"graniteCount":10,"graniteMinHeight":0,"graniteMaxHeight":80,"dioriteSize":33,"dioriteCount":10,"dioriteMinHeight":0,"dioriteMaxHeight":80,"andesiteSize":33,"andesiteCount":10,"andesiteMinHeight":0,"andesiteMaxHeight":80,"coalSize":17,"coalCount":20,"coalMinHeight":0,"coalMaxHeight":128,"ironSize":9,"ironCount":20,"ironMinHeight":0,"ironMaxHeight":64,"goldSize":9,"goldCount":2,"goldMinHeight":0,"goldMaxHeight":32,"redstoneSize":8,"redstoneCount":8,"redstoneMinHeight":0,"redstoneMaxHeight":16,"diamondSize":50,"diamondCount":1,"diamondMinHeight":0,"diamondMaxHeight":255,"lapisSize":7,"lapisCount":1,"lapiCenterHeight":16,"lapisSpread":23}

There are many more, I was just playing around with it!

World Borders
World borders are like forcefields, where you cant pass. By default it is sized as 3 million, and is like invisible bedrock, just like on MCPE, just much bigger. To set one, type "/worldborder set SIZE" if you use a spawn egg to spawn something in outside the border, it will die. If you go into spectator mode, that is the only way to pass the border.

New Endermite Model
It used to be like a purple silverfish, now a purple blob thing. It has one eye, and wiggles around.

Conclusion
So this concludes my article about the latest snapshot 14w17a, have fun with it!