I doubt this'll make it to who would know about this but... During the GameJam for Skyrim a LOT of updates/upgrades were shown off for the game. However a little less than half of the mods were actually released as DLC or in Updates. What happened to the rest? What WILL happen to them? Is there anyway that the creators can release said mods to the people to use in their games or is the code/resources Bethesda property? If the latter is there any hope of the work seeing the light of day?

Personally I'm quite interested in the flow-based water shaders and the seasonal foliage. Along with the Verlet surfaces for non-rigid objects and the spears.
At the very least do we know the future of the Skeletal Butler?

List of things previewed at the GameJam

A lot of things you want are actually in the game already, lookie http://www.uesp.net/wiki/Skyrim:Game_Jam

But some might need engine updates (like SSAO, seasonal foliage, and flow-based water shader) and I wouldn't count on them.

There's probably no chance of the unused GameJam content ever seeing the light of day again unless used in the next singleplayer TES game. The code and resources are likely the property of Bethesda, as they were created in the workplace as part of their job. If I were to make an educated guess, some of this stuff like Seasonal Foliage, Pitch-Black Dungeons and Flow-Based Water would require major rewriting of basic engine functions in order for it to work properly on a large scale.

It's possible that the seasonal foliage was simply just a small area of wilderness with maybe a quest script with extended unreleased Papyrus code controlling texture and mesh swaps, which wouldn't be feasible on a wide scale, and even if it happened to have been done through rewriting the engine code, I'm not sure how feasible it would have been to release that as a simple engine update. They definitely were testing out this stuff like dynamic seasonal foliage, moving platforms such as swinging bridges and realistic darkness while they were developing Dawnguard (there's test cells left over that points toward this), though they may have decided that it would be more worth it to integrate it from the start for when they do TES VI.

A distinct hint at the idea that TES VI may be set in High Rock, and in my opinion, if they want to do High Rock, I think they should do it properly and include dynamic seasonal foliage like in Daggerfall, because that's easily one of the coolest features present in that region in TES II. There's hardly any games today that feature dynamic seasonal foliage.

Pitch black dungeon is featured (somewhat) in Dragonborn, as shown in the link above.

Some of these have been added in by user-made mods.

We could probably do with a complete list somewhere, but for now here's a start:

Water Arrows - http://skyrim.nexusmods.com/mods/12555 is just one of many.

New follower customisation, commands and favoriting - EFF (http://skyrim.nexusmods.com/mods/12933), UFO, AFT.

Goblins and new draugr - Immersive Creatures (http://skyrim.nexusmods.com/mods/24913)

SSAO - ENBSeries

Footprints in Snow - Footprints (http://skyrim.nexusmods.com/mods/22745)

Fire arrows, ice arrows - plenty of mods available that add these

Paralysis Runes - included in Lore-Friendly Spells (http://skyrim.nexusmods.com/mods/34620) and possibly available elsewhere.

Varlet textures was released in Dawnguard but was hard coded to only work with 1 object, Lord Harkon's Vampire Lord cape. It can be manipulated to change the capes color and have multiple of them but it is rather tricky and the colision for it is a bit wonky as it can get flipped through the body and turn into a apron.

As for some of the other things I would agree with Arthmoor that the PS3 debacle ate up the time and money needed to properly develop them and DLC.

Actually, some of the stuff you dont have marked as being added have

-Paralysis runes were added in a way with the Ash Rune in Dragonborn.

-Dragonborn added the Hulking Draugr, a new high level Draugr type.

-the underwater visuals weere actually tweaked a bit when they fixed the water see-through bug in a patch.

-Fire and ice arrows were added in Dawnguard with the crossbow bolts.

Yep, you're right.

Just found a list at the UESP, listing gamejam features and showing whether they were implemented - http://www.uesp.net/wiki/Skyrim:Game_Jam