Legends of Tomorrow Trailer References Superman and Batman

"I've seen Men of Steel die and Dark Knights fall," Rip Hunter says in the trailer for DC's Legends of Tomorrow, released less than an hour ago.

And with those words, Batman and Superman are officially part of the DC Universe as told by The CW's Arrow and The Flash.

Prior references to the Man of Steel had been left on the cutting room floor, and the series premiere of The Flash had an Easter egg about Bruce Wayne.

Up until now, The CW series have not explicitly referenced DC's biggest heroes, with the general assumption being that those characters were off the table for Arrow and The Flash. With the rise of DC's Legends of Tomorrow, though, it seems everything is on the board -- even if it's unlikely we'll actually SEE those characters right away.

"There really isn't anything we've asked for that was not given to us, you know? The show's call Supergirl and it's about Supergirl. It's not like we've been jonesing to have Superman on it," explained Supergirl executive producer Andrew Kreisberg, who also works on Arrow, The Flash and Legends of Tomorrow, in a recent ComicBook.com interview. "We also didn't want to...you know, if you're going to cast Superman, you've got cast Superman right! Just like when yout hink about all the time and effort and energy that's gone into finding the cinematic Superman over the last thirty years."

It's also interesting to note that, given the exact quote, it calls to mind the The Death of Superman and Knightfall storylines, which took place in close proximity during the early '90s.

When heroes alone are not enough… the world needs legends. Having seen the future, one he will desperately try to prevent from happening, time-traveling rogue Rip Hunter is tasked with assembling a disparate group of both heroes and villains to confront an unstoppable threat — one in which not only is the planet at stake, but all of time itself. Can this ragtag team defeat an immortal threat unlike anything they have ever known? DC'S LEGENDS OF TOMORROW stars Victor Garber ("The Flash," "Alias"); Brandon Routh ("Arrow," "Superman Returns"); Arthur Darvill ("Doctor Who"); Caity Lotz ("Arrow"); Ciarra Renee ("Pippin"); Franz Drameh ("Edge of Tomorrow"); with Dominic Purcell ("The Flash," "Prison Break"); and Wentworth Miller ("The Flash," "Prison Break"). Based on the characters from DC Comics, DC'S LEGENDS OF TOMORROW is from Bonanza Productions Inc. in association with Berlanti Productions and Warner Bros. Television, with executive producers Greg Berlanti ("Arrow," "The Flash," upcoming "Pan"), Marc Guggenheim ("Arrow," "Eli Stone," "Percy Jackson: Sea of Monsters"), Andrew Kreisberg ("Arrow," "The Flash," "Eli Stone," "Warehouse 13") and Sarah Schechter ("Arrow," "The Flash," upcoming "Pan").

The series debuts on January 21, 2016, at 8 p.m. ET/PT on The CW.