Hiya.

I bought my ZBrush at v3, so not too long ago. I think I paid about $550 Canadian for it (about $500 US at the time, iirc).

To put it in contrast...it's like Conitec giving me A5, A6, A7 and A8 Commercial *for free*. I only *wish* other companies were as cool and as confident as Pixologic!

As for usefulness...you can export everything...including hair. You could always use the hair you create in ZB4 to make your texture, alpha, spec, etc. maps and then put those on your model. There are so many different ways to use ZB4 for game content it's not even funny. Seriously. Not funny. In fact, just thinking about it is annoying me...all these cool-ass things I could do, but absolutely NO time to use even a 10th of what I can imagine. *sigh*

Now, if someone could somehow magically convert the ZB fur/hair into some kind of DX Shader dohicky that would render with DX10 (or is it DX11 that has a 'hair' shader?)...

Not only that they put their logo on Sculptris after they bought it (which is totaly ok) but they also claim to be the "Makers of Sculptris".
I don´t see what´s cool about that especially since this awesome tool has not been further developed since Pixologic got the copyrights.

Tomas Pettersson did join Pixologic, I believe, so "Makers of Sculptris" seems accurate enough for me.

Not for me since he developed it before Pixologic made him to join them (as we all know).

Now, if someone could somehow magically convert the ZB fur/hair into some kind of DX Shader dohicky that would render with DX10 (or is it DX11 that has a 'hair' shader?)...
No because this Zbrush hair is simply polygons.
Shaders are only polygon surface ligtnening and process effects like full screen effects.
You should search on how hair is done on big quality models.
And for today games you can't make hair driven by million of polygons also

For sculptris, i htink Zbrush knwe very fast , that tiny but very easy, powerfull tool , could quickly become some big competitor.
Specialy that Sculptris with it's continuous subdivision and control on surface like "polygon decreaser " tool !

It has become very fast popular, that sad the author gave the tool to them for money (for him it was just an hobby unfortunatelly)

But well we have it with Zbrush , so we will not complain !