According to the press release issued announcing the branding of DC across all Warner Brothers media, All-Star Superman by Grant Morrison and Frank Quitely will see a three month delay from it's original September launch date.
No reason was given for the delay by DC in response to Newsarama's inquiry.
Sure there's a reason. Frank. Quitely.
I've been expecting this announcement, just thought it might come later than THE FIRST ISSUE! Bwahahahahaha.
In fact, I expect several delays.