I did some searches but didn’t find anything, it would be a great feature to be able to paint on your model with 16 or ultimately 32 bit images, say OpenEXR particularly!
There’s a great 3 part YouTube video on doing this in Mari to paint HDRs onto objects:
http://www.youtube.com/watch?v=1d8ypguQjFw
I hoped something similar could work in ZBrush however using Spotlight you can’t seem to load 16/32 bit images aside from PSDs, and the PSDs just paint artifacts. 