It would be really cool, if it was possible to animate the focus distance (combined with a narrow depth of field), making it possible to create those eye candy focus sweeps across your 3d-model 8)
Just a quick thought :)
You could try rendering depth pass and use it to animate dof in post ( after effects or nuke for example). It will work to certain degree, but it's a bit of "dirty" way to do it.
Better way would be to setup scene and animate camera attributes in 3D app of your choice ( Maya/Max/Cinema4D...) and export it as fbx file. But it looks like keyshot doesn't recognize animated focus distance attribute from Maya.
I'd like to hear more thoughts on this from someone more experienced with keyshot than myself.