I personally hadn't ever thought of the dark-elf or drow, however we are looking at it race, to have an inherent interest or quality to actually levitate?
They spent their lives in the underdark, underground.
I really do not see why they'd ever need, either historically or otherwise of a natural levitation?

In traditional drow legend, they can faerie fire people and levitiate themselves.

Drizzt does it in the story where he goes back to the underdark. (starless night???).

Living underground does not mean levitation would be inappropriate.

For example, a drow might want to lurk in ambush amongst staligtites.

I gotcha, yea I was not sure myself, having no time to read, yet always had the ability to mud on occasion.

At the same time, it has been said that the Immortals intend a gradual shift of the dark elves away from D&D drow. Or at least gradually away from the Forgotten Realms variety famous to the Drizzt books. (they did originate in the Greyhawk setting first, didn't they?)

Why? The Forgotten realm Drow rock!

That which does not kill us,
makes us stronger.