But I got a screenshot of High Hrothgar in the background of the Dragonborn trailer.

http://i.imgur.com/2UBsb.jpg?1

This most likely means that Dragon Riding can take place outside of Solstheim.

You're not the only one.

It's actually been a major point of discussion, particularly the nature of dragon riding.

If it's gonna be confined to the area added in DB or if it's gonna be everywhere.

Argument for it being everywhere comes back to the picture.

While against, insists that is a cut scene or promotional picture an the game isn't designed to handle us being in the air at present.

Noticed and discussed on day one, hour one.

I'm surprised there isn't thread #29 about it. The dragonborn speculation thread (prior to no confirmation) had like what, 30+ threads? Of course, I suppose there is only so much to say.

Could be, or it could just as well be the only way we can get to Solstheim. Maybe you get the quest from a dragon thats been scared [censored]less because of the return of the first DB, and that simultaniously brings you to Solsthiem and teaches you the basics of Dragon Riding.

Either way would make me happy honestly.

No one is talking about it because there isnt anything to say,really lol.

Maybe we can use the background to calculate the height of the dragon! Maybe some math magic can give us air speed! THINK, GENTLEMEN!

What's it's airspeed carrying a coconut?

I suspect what happens is that you, the last DB, are summoned to High Hrothgar by the Greybeards letting out a yell, like they did when you absorbed your first dragon soul. When you arrive, the Greybeards will be there, along with that big black dragon (who looks a bit like Alduin to me.) Either the Greybeards, the big black dragon, or both of them will relate a tale concerning the appearance of ANOTHER dova in Solstheim, upon which you will be given a ride to the island by Big Blackie.

That's my guess, anyway.

You'll probably learn a shout, too, that allows you to call Big Blackie every time you need a cab.

I'm certain someone posted exactly the same thing a few days ago, weird.
But yeah, it takes place in its own world space, what the LOD is like though, IDK. You'll be able to see RM and HH though