Multiresolution mesh sculpting - carve multi million poly meshes at multiple resolutions (or for really high poly counts turn off the multires and really crank up the polys). There are some unique and interesting features brought to the table here with procedural based texture brushes. You are also sculpting in true 3d space. And able to access multiple views simultaneously.

You can also shape your multiresolution mesh using standard mesh editing tools such as loop selection.

Retopology tools - sculpt the rough form - then use paint based or mesh based tools to remake your topology on top of your sculpted mesh.

multiple uv map sets - Blender can now handle multiple uv sets

fast texture and lightmap baking

renderpasses

improved physics

and a huge list of other features - note that the release notes are a work in progress