It'll be like the gameplay trailer, which was epic.
It won't be like the Super Mutant Behemoths, which were "hurr, durr, Behemoth smash!" then you catch them on a piece of terrain trapping them and smoke'em at your leisure.
When i think of the dragon fights in skyrim. I somehow relate this to the Behemoths in fallout 3.
I am only afraid that the dragons in Skyrim will be in fighting hug range of you and thus makes it very similar to the Behemoths fights in fallout 3.
http://www.youtube.com/watch?v=ESeVHLFnIKk
Dragons in Skyrim have multiple behaviors, attacks, and animations. Fallout 3's Behemoths would just aimlessly clobber away at you. You can be assaulted from above with fireballs and dive bombs or ravaged on the ground by different kinds of dragon shouts and bites/slashes. It will be about 100x better.