So as most people know, user created mods have been a huge part of the Elder Scrolls series success. In Morrowind, Oblivion, and Skyrim mods kept the game going long after the developers bowed out. Fans of the series have improved the graphics and created new questlines and other content that made the experience better and longer lived.
In an MMO, new content is the most important thing to keep the game alive. Yet, developers often have trouble keeping supply commensurate with demand. People burn through content faster than they can release it. The community, which is often willing to create good content for free, is too often an untapped resource.
If TESO would like to be a true successor to WoW, with millions of players still active for a decade after release, they should not let this resource go untapped.
They have already announced that there will be UI mods in the game, but honestly that is a pittance compared to what TES fans are used to.
My suggestion is that they implement something like Neverwinter's Foundry: http://nw.perfectworld.com/about/foundry
The Foundry allows players to create dungeons and even quests which other players can then play through. Knowing how great the TES mod community is, I think this feature would fit even better into TESO.
What do you think?