Some movie trailer parodies work well because of the intricate editing work of their creators, with cuts timed perfectly to musical moments that emphasize, always, the exact opposite emotion that the image itself was intended to conjure.
Part of why "My Ultron Will Go On" is so pitch perfect, however, is because how little appears to have been changed from the trailer. It is almost cut-for-cut the same as the trailer released last week, with only one stand-out moment of editorializing — Captain America opening a door timed with Celine Dion's "you open the door..." from "My Heart Will Go On."
Now someone has to put the Ultron trailer to "Solsbury Hill." That's a movie I'd like to see.