Patch 2.4.2 is more than just a client, of course. The content update contains several new skills (such as Blade Flurry), a revamped fog system, an improved chat user interface, and a dozen or so improvements to the Forsaken Master missions.
“In order to provide a smoother experience at the launch of December’s 2.5.0 update, this 2.4.2 update contains many of the improvements intended for 2.5.0,” Grinding Gear said. “Enjoy!”
The studio is also holding a large sale on over 30 of the game’s microtransactions if you want to get an early start to your holiday shopping.
Source: Patch notes