I just personally dont see bethesda as good enough programmers to pull that off yet. Personally if you could free fly that would be better, but just going off of bethesda's track record and how good they are at programming and making animations i dont think you're gonna be able to take a dragon and fly wherever you want. Dragon Riding is a feature added in The Elder Scrolls V: Dragonborn that grants the ability to temporarily tame and ride dragons. The way i read about it saying that dragon mounting is going to be in its own world space, might mean you can only mount a dragon on a dragon vs dragon battle above the ocean between solthsiem and skyrim (so the player cant hit any obstacles) and cant free fly anywhere.
It IS the biggest mountain in tamriel, so you should be able to easily see its massive form from solthsiem. Hell he could be right above solthsiem in that shot, and you can still see the throat of the world from solthsiem. Just because it shows the throat of the world in the background doesnt mean that you can fly anywhere in skyrim. Whole skyrim is available as we can see the dragonborn flying near Throat of the World in the trailer. It would be to fly around the whole skyrim with a level 5 character.
It's going to be awesome, but I hope it's only available after the MQ (the whole DLC).
