Your ping now shows your real connection to the server. Before, it also counted the time your computer spent drawing a frame, so on a busy scene it could read about double. The detailed FPS meter shows both numbers side by side.
The game uses less of your computer's processor in towns and fights, which helps most on older or slower machines. Nothing looks any different.
Server network tuning for smoother play on Wi-Fi and slower connections.
In the desktop app, a downloaded update now installs straight away when you're not in a world. If you're playing, it waits until you leave.