This new update is free for existing owners of the game, and launched two days ago for US owners and launches tomorrow globally. In my opinion, WL2 is one of the best video games in recent years, and a great way to spend your time while waiting for Fallout 4.
Details here: https://wasteland.inxile-entertainment.com/backer-information/release-faq
Wasteland 2 Director's Cut changes a huge number of aspects of the game. Our main new features and changes include:
Graphical overhaul and update to the Unity 5 game engine.
Expanded voice-over with thousands of newly-voiced lines for key characters and scenes.
Precision Strikes system allows you to target individual body parts on enemies in combat, which lets you inflict negative status effects on them.
Perks system lets you pick bonuses for your characters as they level up.
Quirks system lets you pick a personality trait for each custom created Ranger during character creation, with a gameplay-modifying positive and negative quality.
Rebalanced gameplay, including virtually all combat encounters, weapons, loot drops and containers.
Controller support on PC and console. On PC, you can select from keyboard and mouse input, as well as Xbox 360, Xbox One and PlayStation 4 DUALSHOCK 4 controller modes.
There's plenty of smaller additions to be found, of course, but we'll leave those for you to find.
I will add that the rebalanced gameplay adds some nice features, including a much easier system for working with containers/traps/locks/etc. so that you don't have to pick the specific character each time, it just automatically uses whichever character has the highest skill level.
One other aspect of the rebalance is that they reduced the number of locked and trapped chests to make things a bit more realistic and faster to play through. So your average boring loot stuff is less likely to be locked and trapped, but the good loot still may be.
The graphics upgrades look pretty nice as well: