I've been experimenting with this technique for quite some time. It's quite fun. I've made nutella powder, almond butter powder, olive oil powder and cashew butter powder. Eric is right, it doesn't make it lighter but it does make it easier to deal with. The nutella powder was yummy sprinkled on oatmeal too.
Basically anything that is high fat will do.
I was fortunate that the company that makes these products was nice enough to send me a complimentary mixed case of all kinds of this sort of stuff (they know I am working on a mainstream cookbook so I think that is why they did that).
Just a note of interest... tapioca maltodexterin is in many things like hot chocolate powder and such. It keeps powdered items from caking.