I've recently upgraded to PP2014, and I think it's since then that I've occasionally been getting these bizarre sky-blue artifacts in renders.  They pop up rather randomly, but there does seem to be some correlation with the amount of reflection in the scene.  Strangely, just re-building the exact same scene and re-rendering either redistributes them or removes them entirely.  Any ideas would be greatly appreciated!

While the result normally is different, it can be that you are rendering with all material groups in the same SSS groups.

Try setting the skin, eyebals, cornea in different SSS groups.

All surrounding materials should be in different SSS groups.
It is the lower case in the SSS node.

Also check the material setup in the eye area.

Also check the inner mouth and teeth material zones.  If the mouth isn't open, you can remove all SSS related nodes.

I think he is talking about the light blue spots next to the cornea's.

Look closely.  The entire lower face has a bluish tinge to it.  But on closer examination, I see what you are referring.  Silly me, forgot to click on the image to enlarge it.  DUH!