I think this would be very cool, but only if it was worked on by dedicated dorfs (bay12forums) and done so until perfection.
Intro ideas:
IMHO it would be cool if the trailer started out as a jumble of letters, numbers, and other symbols. The symbols slowly coalesce into a "percievable" (ASCII) dwarf fortress game map. Blue would bleed down a path of "~"s to create a running stream. Greens and other colors would grow from the completed stream to color the trees, ground, boulders, and rest of map. A dwarf symbol then moves near the stream from off the map, and a carp blinks in and out of the visible stream. The dwarf reachs the stream, the carp moves near the dwarf, and the dwarf staggers away leaving a trail of blood. The dwarf then gets within sight of an aesthetically pleasing fortress, collapses, and dies. Two dwarfs emerge from the fortress and retrieve his body. Fade to black.
Another idea:
There is some complex ASCII action going on in the screen, perhaps a goblin invasion (with ballistas mowing both dorf and gobbo down). Through some effect or other, the same scene is represented through a player's eyes/mind: { [screen] -> cackling bay12'er -> *high resolution battle footage* }
I think something such as this would be essential to show that DF is visualized through your brain perhaps moreso than your eyes.
At some part in the trailer, it would definately be good to mention the DF motto. Maybe at some epic/tense part, near the end, have the screen fade black then say "Remember..." followed by some sadistically-pleasing footage (dwarf population dying from FB disease or famine, dwarf army getting decimated by bronze collosus, !!kittens!! drowning in magma, etc) which is followed by "Losing..." fade "Is FUN!".
I would like to contribute, time allowing. Here are my specs:
Dabbling Video-editor
Dabbling Sound-editor
Competent Artist (less so with computer graphic programs)
Talented Layout Designer
Not Script-writer
Basically I could contribute to the design/layout discussions (if any) and perhaps do some graphics.