Originally intended as the series finale, but due to the renewal of JLU for additional episodes, it is now regarded as a "franchise finale"
The plot for this episode was going to be used for a Batman Beyond DTV where Selina Kyle replaced Amanda Waller as the one doing the cloning.
The storyline for this episode took place 65 years in the future, meaning it took place 15 years after "The Once and Future Thing" parts 1 and 2 and the cancellation of Batman Beyond.
Justice League Roll Call: Batman, Dr. Light, Shayara, Stargirl, and Red Tornado.
Justice League Unlimited Roll Call: Bruce Wayne, Batman II, Green Lantern, WarHawk, and Aquagirl.
Lauren Tom returns as Green Lantern from the Batman Beyond
episode "The Call part 1
Terry: (To Green Lantern) Batman is dead.
Amanda Waller: I used a piece of Bruce's D.N.A. It was easy enough to obtain. He left it all over town.
(Terry raises his eyebrows)
Amanda Waller: Not remotely what I meant.