So, I have really been playing around with the ideas of corporate nobility a lot. I think what I have decided to go forward with is a group of about 5 Mega-Families, who are the oldest, strongest, and most diversified, globally. Each of these Noble Houses is responsible for controlling a signficant portion of the world's wealth. They each have different specialties and backgrounds. They are involved in various industries and deal primarily within the family for gathering of materials, resources, etc. as well as the sale of their goods and resources to the public.
However, in addition to these 5 Large Noble Houses, very similiar to Conglomerates, There will also be a, yet to be determined, number of other smaller Noble Families, each with varying levels of business-mindedness and essentially making up smaller corporate entities.
There will also be another noble caste within the upper echelons of the world, represented by the Beast Folk, who have decended from the Great Beasts of legend, and are respected, for the bloodlines, throughout the world. Think Minotaur, Naga, Kenku, etc. These races will be more closely tied to the upper elite, and will possess a great deal of respect, but not so much on the corporate side of things.