Again, the OP makes this statement:
Consistent with this ethos and spirit to help you, the artist, unleash the creative beast within, we are currently developing other exciting future products.
As a taste of things to come, Pixologic would also like to give you a little appetizer ‘goodie’, an Alpha version of Sculptris for Windows - a unique, very ‘cool’ artistic modeling application still in raw baby stage and now incubating at Pixologic HQ.
Developing ‘other exciting future products’. That doesn’t sound like simply incorporating new developments into ZBrush - it suggests Pixologic are intending to extend their range, and the following paragraph suggests Sculptris is part of this.
It’s entirely possible to have two related products with a different interface. The major differences between the two products are navigation and look and feel. ‘Lite’ versions tend to be more simplistic and aesthetically pleasing in the UI, as it attracts users with different approaches to professionals. They want to be able to do something cool quickly. A professional wants to do something useful quickly as part of his or her workflow, but with more flexibility and power - there’s a difference.
I’m sure when the dust settles on ZBrush 4, we’ll find out a bit more.
By the way, apart from the crease tool, I also found zooming using the mouse wheel very handy. It’s something I wish ZBrush had (along with the current Alt-LMB combination).