While most of the characters depicted on the cover, the majority have them have come in teensy little cameos, and most of those were just retelling events that had already been shown elsewhere, in other DC mags. Supergirl, for example, appeared briefly at Black Canary's bachelorette party, and that's it. Most of the JSA members depicted showed up in retellings of portions of the Lightning Saga, which had already concluded weeks before Countdown got around to mentioning it.
Superman, Batman, Wonder Woman? Despite some substantial possibilities, they're not really in this series AT ALL, despite their presence front and center on the cover.
And the characters the series is really about? Jimmy Olsen's nowhere to be seen. Only Jason Todd makes the front cover. Donna Troy, Kyle Rayner, the Atom--shoved off onto the "hidden" third page of the cover. Mary Marvel? All the way off to the left on page 1. Piper and Trickster? Nope. Holly and Harley? Nope. Karate Kid and "Una?" Yeah, but you can't really tell who they are, and they're buried amidst the crowd on page 1.
So, Paul Dini, Dan DiDio and Andy Kubert et al? Liars, liars, pants on fire. I'm just sayin'.