http://www.cbr.com/scott-snyder-joke...-nights-metal/
“Geoff [Johns] was great about walking us through what the plan is for upcoming ‘Three Jokers’ storyline and giving us the breathing room for what we wanted to do. Just to be clear to readers, this is not going to answer the ‘Three Jokers’ question” Snyder said. “That’s really for Geoff — he has a big story planned for that — but what it will do is show us the way that The Joker, like he did during my entire time on Batman, is always there as the Greek chorus of the book, saying to Batman, in one way or another, ‘You’re doing it wrong,’ or, ‘You’re doing it right. This is what needs to happen. This is who you are.”
I don't know about you guys but I breathe a sigh of relief here in knowing that Rebirth is still it's own thing (READ BELOW) and that Dark Days and Metal and all this other background noise is it's own thing as well. It's a pity with the mystery of the tuning fork being one hell of a McgGuffin and is literally the only reason I will be reading the story as it sounds like another bag of empty promises disguised as universe breaking/defining shenanigans. Why they aren't saving this event or at least the concept of the Tuning Fork for Rebirth related material is beyond me. Especially because it seems the Tuning Fork is obviously from one of the other Crisis timelines as we haven't seen one in the Nu-52 (Unless I am wrong in there being Tuning Forks in either Darkseid War or Multiversity) and could be used within Doomsday Clock as well obviously as it seems like the Multiverse is in play there as well given what has happened in and to Superman from Convergence thru Reborn. It's a good time to be a comic fan again. Haven't been this excited for an event since Infinite Crisis. I have other threads with this theory in it and other analysis/speculation and I will continue to add to it.
I think it's pretty obvious what is going on with the Three Jokers storyline which my theories on it were only strengthened by the outcome of "The Button" in that there is either 1 Joker with 3 distinct personalities ergo making him 3 to the universe and therefore some sort of powerful anomaly considering he has always had a sort of sixth sense when it comes to the cosmic threads of reality (especially after having been Emperor Joker) or there are literally 3 Jokers and they live within the 3 eras that we saw being kept together in The Button of Pre-Crisis/Post Crisis/Nu52-Rebirth. However, this is where my thinking gets incredibly bold......so hold on to your hats here kids.
I believe that Dr. Manhattan is the Cosmic Hand that makes the DC Universe. I believe and believed this since the beginning of REBIRTH that Doctor Manhattan is the creator of the DC Universe and is now manipulating his lifeforms he said he wanted to create at the end of Watchmen by taking love and in some cases HOPE out of the equation.
One last thing. I believe OZ is either Superboy Prime or Alexander Luthor Jr ala Infinite Crisis. Just let that sit and stew for a bit. :-)