Of the 52 books, there is no mention of the The Justice Society or others from that series, with the exception of Mr. Terrific getting a series. The Wildstorm Universe of characters merged into the DC Universe with 3 books - Grifter, Stormwatch and Voodoo. Some of these were my favorites back in the 80's. DC's website has a complete run down of all 52 books.
I'm not sure how I'm liking this idea. They missed the bus years ago when they did Crisis on Infinite Earths. They've tried to correct it through the years, which made things even worse. Marvel also tried a similar thing with Heroes Reborn. Captain America, Thor, Iron Man, The Avengers and Fantastic Four rebooted their history in an alternate universe. Reception on that wasn't too well received, even with creators like Jim Lee and Rob Liefeld on the project.