User blog comment:Kacj321/The Elder Scrolls V Skyrim - Official Trailer Gameplay/@comment-69.136.17.96-20110305071720/@comment-2081141-20110322212457

They'll be here as summoned creatures (conj isn't much fun without them), and possibly in conjurer dungeons (or a skyrim equivalent) but not as a main antagonist. Also, apparently one of the dragon shouts summons a friendly dragon to you for a short period of time.

But honestly, I think it's better not being able to have one help you, because it takes away from the sheer epicness of fighting an army of dragons.