Looks good, similar feature-set than ZBrush or Mudbox. The big challenge when building these kind of software is handling the staggering amount (multi-million) of polygons that need to be transformed and manipulated in real-time by the artist. To achieve this, ZBrush relies on pixols (voxel-like 3d pixels) and Mudbox uses advanced gpu-accelerated 3D partitioning. Sculptris seems to be more akin to Mudbox.
Very cool video that seems to have inspired a lot of people. Farsthary's now working hard on "unlimited clay" for Blender's sculpt tools: