Age of Conan's Dreamworld engine upgrade, and Funcom has made the extensive notes available as it deploys the update to the live servers. Dreamworld features improved memory handling, loading times, framerates, and network latency as well as several visual upgrades (including the addition of tree wind, god rays, and higher-quality water for DX9 users).
The 2.1.3 patch also brings a few notable tweaks aside from Dreamworld, including minigame class balance fixes and the ability to purchase Khitai faction items (including simple trophies, marks of acclaim, and imperial insignias) with veteran tokens.
Age of Conan's launcher notes that "this is part of the current focus on improving the faction progression in Khitai, which will continue in subsequent updates with a significant increase in the speed of progression for faction." Check out the full patch notes on the official AoC forums.