Schedule Slip: The comic was first revealed in 2007 and the intent was for one of each of the twelve issues to be released each month. The comic wasn't printed in its entirety until 2012, five years later. A news story archived from Marvel's site here states that the comic was the victim of its own success - both writer J. Michael Straczynski and artist Christ Weston had suddenly become hot talent, which took them away from the book for quite a while.
General trivia
While most of the featured characters in the miniseries have very little known (and in some cases literally unknown) creators, some had more of a famous pedigree. Captain Wonder was co-created by Otto Binder (who'd later co-create DC's Supergirl and be of crucial importance to the Shazam family), Fiery Mask by Joe Simon (who'd hit big co-creating Captain America at Marvel and the original Sandman at DC), and The Witness by none other than Stan Lee (in one of his earliest creations in comics).
states that the comic was the victim of its own success - both writer J. Michael Straczynski and artist Christ Weston had suddenly become hot talent, which took them away from the book for quite a while.