http://www.zbrushcentral.com/showthread.php?71266-Pixologic-Release-3D-Print-Exporter

Right below the cobra is 8 more links to 3D Print threads.

I've never made 3D Prints my self.
It's my understanding if you need a smooth mesh
you need to raise the polycount high.
zBrush can have a billion polycount.
 
Yes a billion
http://www.pixologic.com/zbrush/features/HDGeometry/

3D Printers are very cool.
I wouldn't mind to have some of my meshes setting around the house as statues.
Then ya would need to paint them.
unless you spend a lot of time painting all the detailed textures.
ya would just paint it like marble or something.lose all the textures.
So I'm waiting till 3D Printers can copy the mesh and the textures.
For now posters on the walls.

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Not that zBrush has been famous for good topolagy.

C4D supports nGones ,zBrush does not .So you half to make sure not to import nGones in to zBrush.

Even thou V4,V5 is 100% quads.
If you use the zBrush smooth brush over top a vertice that only has 3 lines attached
to that vertice it will raise that vertice a bit higher.so you half to be careful.

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The Artist that will fight for decades to conquer their media.
Even if you never know their name ,your know their Art.
Dark Sphere Mage Vengeance