I've been reading it, since I'm a relative newbie and not as familiar with it as y'all. But I can't say, not having read Zero Hour, that the History of the DCU made me understand what happened in it or why it may have had lasting significance.

And considering about a significant number of the weeks' histories by the end will be referring to continuity that's only been within the past year... ughh. I mean, how likely is it that a large number of folks reading 52 have no idea what happened in Identity Crisis or Infinite Crisis? Not very.

Hands down, I would rather have had full length issues. I am looking forward to the Secret Origins stuff; hopefully it's a lot better than the 'bruce wayne files' from the back pages of Justice.