Not only would I like to see dragons again, but I'd like more aerial enemies. In addition to the big event that a dragon fight is, some more cliffracer-esque "swoop down and then pretty much stay in sword range" enemies would help liven the world up.
As long as these enemies don't
sound like cliffracers, this is alright for me.( see your sig)
I missed to do damage to dragons in Skyrim when they were in air. Proper airfights were you can levitate/fly would be nice.