Since the complete user interface redesign with 2.5, many additional features have been added. This is a summary of some of the major ones.

Click on pics for links to detailed release logs.

Cycles Render engine new features: render layers and passes, multi GPU rendering etc.

Object motion tracking; new UV tools; carve booleans; remesh modifier

Cycles Render Engine; Motion Tracking; Dynamic Paint; Ocean Simulation

3D audio and video; vertex group modifiers and weight painting tools; game engine navigation meshes

Hundreds of improvements to the user interface, internal architecture, modeling tools, animation system, physics, and rendering

New bmesh system with n sided polygons (not just triangles and quads); sculpt hiding; movie clipping

Cycles Render engine new features: panoramic camera, shadows, mirror ball environment textures