There is a tonne of setting conversions for Savage Worlds, but one in particular stands out for its absence: Bethesda Softwork's venerable world of The Elder Scrolls. It's been discussed, but I haven't turned up anything substantial in my searches.
(Edited to add.) Since I wrote this, I've discovered The Elder Scrolls: A Savage Worlds Conversion by the Journeyman GM. It's a huge effort and looks to be very complete, including rules for things introduced by Skyrim. Go check it out!
It's the perfect sandbox setting[1. Incidentally, there is a good Gnome Stew article on non-linear/sandbox games that gives an overview of the gameplay style, and gives a lot of good advice.], with deep background material, abundant maps, plot threads galore for players to chance upon, and a wide world to explore. It's also nearly ideal for my current needs since I can wing it and still have a lot of setting information at my fingertips after many hours of playing TES 4: Oblivion. (I haven't played the others in the series, yet.) As hack/ points out, there is a bounty of adventure ideas to be had from player-maintained sites documenting each game's quests in good detail, including maps. As easy as it sounds to convert to d20, it will be even easier to convert such adventures to Savage Worlds.
There are a good number of people familiar with the setting through the video games, too. That lowers the player buy-in for those players, although it does mean I can't steal quests whole-cloth for the campaign. That's just as well though, since I want to avoid the temptation to just rehash Oblivion. The real strength of a pen-and-paper game is the ability to go anywhere and do anything. Although The Elder Scrolls series of games are delightfully accommodating of that desire, a tabletop game is just so much more flexible than anything that computers can produce so far.
The one challenge then, is not building the setting, but wrapping Savage Worlds mechanics around it. There's a lot to work out, but fortunately the system is simple and flexible enough that what would be a monumental task in d20 should be something I can actually accomplish in SW. The biggest mechanical hurdle is how to handle magic, since everyone has a little bit of magic in The Elder Scrolls.
The other challenge ("Two! Two main challenges..."[2. Everyone still gets this reference, right?]) will be distilling the setting details that will get unfamiliar players engaged in the sandbox. An overview of the races and their relationships, the provinces of Tamriel and local geography, and recent history will be necessary, but have to be conveyed in few enough words that I can depend on my players reading it.
So! With all that in mind, I'm prodding a skeleton of a Google Doc into a useful conversion. I'm sure you'll see pieces of it here at some point. Any fellow Savage Worlds and TES fans out there? Do you have any suggestions for how to tackle the various setting details?