A post on Battle.net discusses plans to increase the draw distance in World of Warcraft in the upcoming Legion expansion for the MMORPG, adding the ability to see more distant objects, and adding textures to things previously seen as silhouettes (thanks Ant). Here's more on the process, including how it involves the addition of LOD for game models, something you might assume was in there from the start, as it is not a cutting-edge concept:

There are two numbers that contribute to how far the player can see terrain and structures in World of Warcraft. These numbers are the “fog distance”—a depth from the camera at which point any object’s pixels are fully converted to the fog color—and an overall draw distance, after which we clip all object geometry, preventing anything past that point from drawing. On lower settings, you can see the second value as terrain and buildings seem to melt into existence, fully fogged, before slowly getting colored as you get closer to them.

In Warlords, the highest-end hardware that can reliably run the Ultra setting manages to push the fully fogged distance to about 1,300 “game units” (yards). After that point, all objects would be drawn filled in with the fog color until the clipping distance. The same setting in Legion will draw out to 2,600 game units. Those who currently play at High settings in Warlords and see out to 1,000 units will see 2,200 units in Legion. Graphics Level 10 is currently set at 3,500 game units, which you can see in that last screenshot. It’s important to note that due to memory considerations, all of these new draw distances are only available in the 64-bit client.

If you’re interested in the “how,” a bulk of the effort to achieve this went into changing the way we draw terrain and water in WoW to render fewer vertices at a distance. But it also necessitated the implementation of Level of Detail (LOD) for game models, like trees, and buildings as well. A model with LOD can swap to a lower polygon count model at a distance without negatively impacting the visual quality of the scene. We prototyped aspects of these systems in both Warlords of Draenor and Mists of Pandaria and learned enough from those two expansions to feel confident about making this change in Legion.