I have a feeling this is the end of the free program as we know it. How sad. I still have a copy zipped some where i was giving it out to my nieces and nephews. I could not buy them all Zbrush, so Sculptris was the solution. too bad not anymore i guess. at least i have the latest beta copy. 
I suppose i saw this coming. Congrats to the Developer. But a sad loss to the free 3D app community. I did see a blerb on Blender nation where they were adapting the technology into Blender sculpting. So perhaps it wont be a complete disappearance.
Smart move of Pixols part. I would have done the same thing from a business standpoint. Don’t take my post the wrong way. I’m just a poor struggling 3D artist . I could only afford a few programs. Zbrush being the most expensive. I have to suffice with Blender for box modeling… (shudder)
I was considering Silo, but they haven’t updated in 3 years… I think they are going down.
Pixol, I appeal to you, please keep Sculptris free.
~ Gridlost :o