The various changes made in the Infinite Crisis hardcover edition have been making the rounds on various message boards (along with this double page spread re-drawn by George Perez SEE THE LINK ABOVE TO SEE THE ART). I got this summary and analysis from a poster on the Geoff Johns forum:
There are several flat out hints that Earth-2 is coming back/still exists in the new IC HC. These line changes completely change the previous meanings in the monthly issues.
1.) In IC #5, GrannyLois is dying, trying to get Kal to realize he's been in denial. Lois says, "With all your powers, with everything you saw and did... you still never..." Clark says, "It can't end this way," and Lois says, "...It's...not...going..." and then dies.
HOWEVER, the new test has Old Lois saying, "I see the truth now, Clark. A truth even Alexander didn't see... there's something else out there... out there..." Clark still says, "It can't end this way," and LL still says "...It's... not...going..."
QUITE a significant change. Of course, this could mean "Heaven", but I think it means Earth-2, when combined with the next examples.
2.) Also in IC #5, the Wonder Woman of Earth-2 gives her spiel, but one line is drastically changed. "But now that I've left Olympus, the gods' blessings are fading. Soon I'll no longer exist."
In the new version in the IC HC, Wonder Granny says instead, "But now that I've left Olympus, the god's blessings to keep me here are fading. I'm being…pulled...somewhere."
"Somewhere", just like Lois knowing there's something else out there, hidden from Alex.
3.) In IC #6, when Alex is mixing up the various Earths, Psycho Pirates makes an observation: "I can feel them. Phantom beings from the fabric of Earth-One and Earth-Two, pulled from their restful place, reborn in pain and given essence -- then destroyed. Billions at a time."
Alex replies, "I planted this garden, Psycho Pirate. I have every right to tend to it."
MEGA-MAJOR changes occurs in the HC, where PP says instead, "I can feel phantom beings pulled from the fabric of the Multiverse, recreated and destroyed. For some reason, Earth-Two remains vacant. Why when billions of other beings appear across the Multiverse like ghosts. Reborn... then destroyed."
Alex' completely changed reply is, "The anomalies of Earth-Two are not my concern. Finding the perfect Earth is."
So, here, Earth-Two is a special case in all this merging.
4.) In IC #7, SPB is whining that he doesn't like Earth-One. Alex replies, "This isn't Earth-One, Superboy. It never was. And now this "unified" world, this New Earth has been altered again. There are changes within its history."
In the HC, Alex' words are significantly different: "This isn't Earth-One, Superboy. In fact, it never was. I tried to divide a New Earth. Instead, I only altered its history."
5.) And the Biggie... When Kal-L is dying in Kara's arms, in the comic book, Kal tells Power Girl he'll always be there for her and now he knows what Lois was trying to say. He says, "It's not going to end. It's never going to end... for us..." then two wordless panels, with Kal looking up into space, then the panel where he says Lois' name for the last time, and then he dies.
WELL..... In the IC HC, those two wordless panels gain some dialogue from Kal. After he says, "It's never going to end for us..." he then tells Power Girl, "...One day you'll see... they're still out there..." Then says Lois' name and dies.
"THEY'RE still out there?!??!!!!!"
Finally, in the interview in the end, Anton Kawasaki brings up IC #6 and "New Earth". Geoff Johns replies: "We always knew we were going to do something with New EarthS. THEY'RE important to "52". Big revelations there" (Emphasis mine).
This Has A “Bring Back The Multiverse” Factor Of Eight Out Of Ten