My makeup artistry teacher, an original MAC pro @ North Robertson, LOVES Vanilla pigment for a highlight. I use it every day, and i looove it. It has a sort of natural-looking goldishness, but is still light enough for my NC15 skin. It gives me a great glow!
She even uses it as a highlight on the center of the nose for more natural looks, mostly on people with kinda middle-range-dark in color skintones, with goldish/yellowy undertones (Think Latino skin, or golden-toned Af. American skin... she used it on a couple of the girls from En Vogue). Basically, if you're a W or NW40+, it should work well. Hey, and I even do the "nose highlight" with the Vanilla pigment when I'm doing "going-out" makeup, and it looks SO GOOD!
She also told us that Billy B (famous, famous LA makeup artist.. you can see his "must have" list of MAC products for his kit on the MACPRO.com website) uses Frost pigment or White pigment (blended EXTREEEEEMELY well) as a highlight on all the highlight areas of the face, and on the decollatage etc.
I hope this is helpful!!