To be honest, I would not be surprised if they add a type of levitation as a Dragon Shout... It already sounds like dragonshouts are effectively more powerfull spell rip-offs.
I only hope they don't go compleately overboard with them and make it so spellcasting is altogether obsolete with this mechanic.
Why not both? Consider having a Morrowind based magic system where magicka wouldn't regenerate - rest, potion, or absorb. Combine that with a levitation spell that constantly drinks magicka. You can control "thrust angle" like a Harrier jet - hover, climb slowly, or translate to speed by dropping altitude. Now we have a spell worth using for those hard to get to ledges and cliffs, or for that reverse dungeon clearing, or to get to that second story door if you're not an acrobat. But all your mental strength should go into focusing this levitation, no spellcasting or fighting, and drinks magicka like crazy depending on how high or fast you are.
Morrowind made levitation far too trivial and ruined the whole concept. The evidence shows again and again in these threads. The levitation fans doesn't want *levitation* they want outright *flying*. If levitation was made something you'd think twice about using, then it works for me. I dragonshouts enables more traditional flying abilities, at least late in the main questline, ir would serve as a desire to do the questline, and it could be limited like a greater power to a once in a day to keep it interesting without unbalancing everything.
Being high level shouldn't take away the need to think.