Been playing with everything maxed out @ 1900x1080. I feel like they went a little overboard with some of the effects and the textures can be somewhat shoddy in some places, other than that it looks great, though.
It's a shame it's impossible to force it to use AA.
Flyable Dragons is all I ask for. Although I suspect that the whole game would explode if they tried to do this.
Not hard to do game design wise, doable even at mod-level. You just have to make sure the dragon is flying slower than the rate determined by the engine for streaming in assets (so that you don't get invisible terrain and shit not loading because its not in memory yet). Also a mod has to account for the lack of gameplay mechanics and animations when on a dragon and do something about that.
The problem with this is that walled towns are in separate worldspaces. So if you tried to fly over one it would look like shit, and you wouldn't be able to land in it. So if Bethesda would make this as a DLC they would either have to incorporate the towns into the "Skyrim" cell (which would be a fucking hassle) or somehow make it so that you wouldn't be able to fly too close to towns.