Blender 2.5 Sculpting - 45 Million Polygons!
Due to the recent improvements in the sculpting branch, Blender now has the ability to sculpt massive amounts of polygons.
Sculpt mode in Blender has been optimized, increasing drawing and editing performance, and reducing memory usage to support more detailed models. New tools have been added and existing ones improved. Multiresolution meshes have also been rewritten, now available as a modifier to integrate better with the animation system, and preserving displacements when editing the mesh topology.
Check out the documentation on the new sculpting features HERE