Originally Posted by sto_vo_kor_2000
Every comic book published by DC comics is "Canon" within its own story.
The question is wether or not the events of any particular story has any bearing on other stories.
And as far as I know [I could be wrong] the only thing that was implied was that Earth 31 was the home of "The Dark Knight Returns" and "DK2" characters.
So far that has been no official connection between Millers "All Star" universe and his "Dark Knight Returns" universe.[again as far as I know].
Frank Miller has stated that All-Star Batman & Robin does take place in what he calls his "Dark Knight universe," officially designated as Earth-31 as seen in Countdown: Arena and stated by Countdown Arena writer Keith Champagne.
Frank Miller himself said, "DC has allowed me to carve out my own "Dark Knight Universe", letting me play with their characters with abandon." http://archive.comicdom.gr/interviews.php?id=17&lang=en
“Anything I come up with about any of these characters is DKU,” Miller said. In his Dark Knight work, Miller has given readers a glimpse into the twilight years of Batman’s career. In Batman: Year One, he’s shared the beginning of the Batman saga. So where does All-Star Batman fall in his Batman time-table? “Year Three. Bats is feeling his oats—very young, maybe acting a little crazy, but he knows exactly what he's doing. He's just a bit sloppier about doing it than he's going to eventually get.” - Frank Miller.
And this Dark Knight Returns character's appearance in Miller's All-Star Batman & Robin makes it obvious that they are indeed officially connected
. Miller has made it clear that All-Star Batman & Robin takes place after Year One and before The Dark Knight Returns and DK2.