With news that Power Girl may not exist in the DC Comics Relaunch, but her alter ego of Karen Starr does, I got to thinking about whether anyone will remember the pre-Flashpoint DC Universe after the September 2011 relaunch.
As context, as indicated earlier, for anyone keeping score, the most immediate pre-Flashpoint DC Universe was only about 5 years old.
It is a different universe than the one that debuted after the 1980s’ Crisis on Infinite Earths which collapsed the multiverse. Folks may remember, that the villain Psycho Pirate was the only one that remembered the pre-Crisis DC Earth One. It drove him even madder than he was before.
After DC’s Infinite Crisis, that brought back a differnt multiverse, it was revealed that DC’s Power Girl also remembered an Earth that no longer existed, the pre-Crisis Earth Two where the Golden Age heroes of the Justice Society of America resided pre-Crisis. She was the Golden Age Superman’s cousin from Krypton.
Infinite Crisis also saw the return of Superboy-Prime. He was from Earth Prime where super-heroes only existed in comic books; basically the “real world” that we readers live in.
However, it was revealed that he was in fact a young Kryptonian named Kal-El, and you know the rest of the story about what happens to Kryptonians on Earth: they gain super powers. Prime was the only super-powered being on Earth Prime, and that Earth that destroyed during the first Crisis. At the end of Crisis of Three Earths, featuring 3 different versions of the Legion of Super-Heroes, Prime was returned to “an” Earth Prime de-powered. 
It’s not clear if it was exactly the same as the pre-Crisis one, but Prime seems comfortable there.
While the fate of Power Girl is unclear in the new DCU as DC is resting the JSA concept during the DC Comics Relaunch, since Superboy-Prime was part of a hugely successful Green Lantern events including Green Lantern’s Sinestro Corps War, Blackest Night, and other events like the original Crisis that still happened in the DCU.
As a result, it’s very likely Prime still exists in the new DCU. Since his whole shtick is to get back to his own Earth Prime, it may make sense for Superboy-Prime to be the only one that remembers the pre-Flashpoint 
5-year old DC Earth too. It would give him an even larger superiority complex and allow some wink-wink moments with readers while taunting Green Lantern or Superman, etc.
However, beyond characters that remember previous non-existent Earths, there are other contenders who could make sense as being the sole character that remembers the past.
For example, there is still a question of whether 
Booster Gold will remember the pre-Flashpoint Earth as he and Rip Hunter protect DC’s timestream. Dan Jurgens, that books writer-artist, indicates that question will be answered in the last issue of Booster Gold in August 2011 even as DC has noted that the timestream is closed (for now) in the DC Comics Relaunch “new” Earth.
However, since Flashpoint is a Flash family event, will it be Zoom, the Reverse-Flash, the one that seemingly caused new time to be created and wipe out the old DCU, be the one to remember the old world?
Flash and Kid Flash currently remember the old DCU in Flashpoint, but their memories appear to be fading, reducing the likelihood that they will remember the old DCU let alone the Flahspoint universe in the new DCU.
Or, here’s a novel idea: will no one remember the pre-Flashpoint confirming Dan Didio’s claim that there is no trap door in DC Comics Relaunch to allow a reversion to the pre-Flashpoint status quo?
What say you?
