From my understanding, levitation is not available in Skyrim. In my opinion, it is unnecessary and adding it would have ruined many elements of gameplay. I cannot visualize how it could have been utilized effectively, and, in my opinion, is was not utilized effectively in Morrowind either. Levitation could be used to easily break quests, bypass difficult areas or enemies, and easily defeat melee opponents, and it was used to do just that in Morrowind by hundreds of people. The benefits include being able to access different areas such as buildings in the sky or mountain climb without effort. If you want to access a building in the sky though, do you really need to have a spell that allows you to walk through the air? Why not have a spell that teleports you to the building? I guess magically scaling a mountain is an OK idea, but that's pretty much the only thing I can come up with.
If anyone else has any ideas as to how levitation could be implemented effectively in Skyrim, please post it, and do try to include examples.