I feel like this is a stupid question, but where did you find these videos? I don't see them on the characters' pages, or anywhere else on the main site.
I usually get on my ps3's Web Browser then youtube and i searched for playstation allstars battle royale, then filtered by Upload date... and i saved that to my bookmarks that way i could see any new videos on PAS whether it was Gameplay, News,etc.
i saw that a channel had these trailers and thought that i should post them here for everyone to see...
If i find one for Drake and Big Daddy ill post them here =]