Unlimited clay is based off the ideas presented by Sculptris. Pixologic hired the guy who made Sculptris, took his already working dynamic tessellation engine, and refined it.
Yay, voxel type sculpting is really the way forward for sculpting apps, I'm kind of surprised Pixologic was so quick to integrate it, looks already pretty much as powerful as in 3DCoat. Can't wait to give a try!
Ace! I've been waiting for this feature ever since Pixologic hired the creator of sculptris! Dynamic tessalation for the win! But agreed with Firebert, I would have loved it if he took those shapes a bit more extreme.