Having never played Morrowind, I'm not entirely sure on how levitation works but if you hear me out you can correct me if I'm wrong.

Bethesda has avoided the prospect of including a levitation spell in their latest Elder Scrolls games Oblivion and Skyrim, for me the reason is clear, most of the cities in these games have to be loaded as you go through the main gates. This is the reason a spell like levitation can't be included in Skyrim, as you could just fly over city walls or even access areas of a cave that are unreachable for a reason. So how do Bethesda include a levitation spell while still keeping the Skyrim world functioning as intended?

It's pretty simple when it comes down to it, the levitation spell doesn't have to be a means of flying, it can just provide the Dragonborn with the ability to hover. Now while this won't mean much while you're running around on ground, it could become amazing at the top of High Hrothgar. The levitation could become a means of descending, a slow and steady descent in full control of the player. As you're about to walk off the edge of a cliff, you cast this spell to begin hovering, once over the edge and there's some empty space between you and the ground, you begin to descend. This could throw up some great Skyrim moments, and expand the Alteration school slightly. The animation would be fairly simple, the Dragonborn would take up a posture similar to http://www.levitation.org/images/Levitation-man-float.jpg but with his/her hands facing the ground and small jets of Magicka coming from his/her palms.

While this won't allow you to do much other than role play in the current Skyrim world, added in a DLC you could create puzzles and/or secrets that are only accessible through levitating. Each level of the spell you get will decrease your vertical speed and increase your horizontal speed which will allow you to reach further distances before you land:

Spells

Float - Adept level alteration spell
Glide - Expert level alteration spell
Soar - Master level alteration spell

Perk

Levitation Mastery - Allows you to cast a levitation spell while you're falling. (Requires Alteration of 100)