Patch 5.0.0 is live, bringing over 50 different game improvements. Here are some of the major ones.

Combat improvements:
3 classes are split into 12 new classes, featuring upgrades to core skills and new passives.
Improved skill effects, rebalanced them, and reworking some to make them more interesting.
Players can now combine classes, and skills are more independent of weapons.
Added a new hard difficulty.
Updated rings to support mastery updates.
Added ragdolls
to enemies upon death.
Added trails
to all weapons in melee combat.
Added new sounds in combat.
Made the camera smoother
and added better camera shake.
Increased character movement acceleration fivefold for easier controls.
Improved bow ranged combat animations.
Added an option to enable character health above the character's head.
General UI improvements
around the action bar.
Added an icon to enable the action bar directly through the UI.
Added new skill tooltips and a new mastery UI.
Updated tooltips, help pages, intro pages, and others to reflect new skills.
Added option to enable extra mastery slots.
Added an undo button to mastery selection.

Major fixes:
Fixed floating precision issues that caused problems with navigation in dungeons and the underworld.
Fixed issues where sometimes AWSD controls would not be as precise as mouse controls.
Performance improvements have been made around how content is loaded from the hard disk.
Fixed some graphical issues that caused ground textures to appear in a worse resolution than intended.