Unity 4 will be released sometime soon, and it’s sure to be fantastic. Here are some of the new features:
BETTER GUI SYSTEM
Much better optimization and performance
Easy and visual animation blending
Easy use of mocap
Use inverse kinematics rigs
NEW USER INTERFACE
Better project organization
Component based workflow
Live preview Asset Store assets within Unity Project window
Unity makes use of Microsoft’s DirectX 11
The ability to use volumetric textures for advanced shader effects.
Updates to the Shuriken particle system for more realism.
Dynamic, real time shadows for mobile
Deployment to the Linux OS supported.
UNITY 4 FEATURES NOT IN FREE VERSION
Mecanim IK rigs
Some navigation mesh features
Lightmapping with normal maps