Using familiar movie soundtracks in trailers is nothing new, but I think these Man of Steel announcement teasers are the first non-LOTR movie trailer to use actual bits of Howard Shore’s score to The Lord of the Rings. And they definitely picked one of the more memorable pieces as the music used in the teaser is from the latter half of the Khazad-Dûm score when the Fellowship is reacting to Gandalf falling with the Balrog.
The two trailers are randomly attached to prints of The Dark Knight Rises, and they both show absolutely identical footage. The only difference is one has a voice over by Jor-El, and the other has a voice over by Pa Kent. You can check out both below,