Quite a few trailers were added to Xbox Live Marketplace this weekend. Besides the two DLC items for GH II and Blue Dragon, these seven were also added:

Video/Trailers

Guitar Hero II: Indie Label Pack Trailer (Free)
Bringing It Home: Halo 3 - Campaign Demo with Bungie Video (Free)
SEGA Rally: TV Advert (HD)
Crash Of The Titans: In-Theatre Trailer (HD)
Battlefield: Bad Company Trailer 2 (HD)
SEGA Rally: Launch Trailer (HD)
SEGA Rally: Launch Trailer (SD)