tl;dr in-game creation kit for SK
Adds a menu that opens up a list of player created levels, has search functions (like every good map list) and sort by buttons (new, rating, plays, popularity, you know the typical stuff) , allows any 30 day or older player (to prevent map spammers) to access a editor like the ones for guild halls but it have every object,pre-set AI, monster,npc, sounds, music and buildings are all available to be moved and placed, you can set paths and behaviours (attack speed, attack pattern, damage, if they speak you can write the text) for everything. Also has integrated support for JDK for advanced users to further build on original/base features. After a level is created instead of saving all the data as images and code (which would take up way to much server space, like 2 or 3 mb per map I would expect) the level's code (including id's for everything , file names of images, AI and location data is all converted to a text file (of around 100kb or so) compressed if necessary then sent to the server to be listed. Just like any editor/creation kit this'll open up almost infinite amounts of content and re-play value that make games like skyrim, castle crusher 3 and minecraft last so long without effort on developers part.
I would love this.
But I don't know if the developers would want it since they're always so strict with their game content.
So we can only hope this "Sandbox mode" in the upcoming update will be a good substitute for a JDK.