My understanding of the new '52 earths' is that they are not the pre-Crisis multiverse; they are simply a way of DC being able to sell title characters with more than one continuity at the same time. See here:
http://www.606studios.com/bendisboard/showthread.php?t=112868While this seems like a good idea to be able to market different product lines to different groups (or sometimes factions) of comic book fans, this could fail as badly as Crisis on Infinite Earths, for these reasons:
1) What about new readers? Who could possibly follow what is going on in the larger, crossoverish DCU right now? Really!
2) Having 52 different earths does not address alternate
timelines, as hypertime did. For example, All-Star Superman and Whatever Happened to the Man of Tomorrow seem to both be alternate splits from the timeline of Earth-1 Superman. (The latter future Superman appeared in Superman/Batman issues, and therefore must exist
some...when?) Likewise, there are the Earth-1 timeline splits of Kamandi's future vs. the Legion's future.
3) Writers and editors who supported the goal of Crisis on Infinite Earths- that is, to "simplify" the confusion caused by 6 or 7 earths, are going to be falling over one another trying to get their hands on the axe this time. Eventually, someone will let them.
4) The main question: did everything still happen? Hypertime allowed for the Marvel universe to exist as part of the DC Universe, in a separate timestream. Did the Marvel crossovers still happen? What about everything else for the last 70 years?