About DC's disorganization: in the new 52,
editors let the writers decide the direction of the series thinking they knew what to do, and they ended up with a mess: multiple takes of the same characters, continuous change of directions, conflicting creative decisions, etc...
Speaking about our fav characters... on Superman, Perez didn't know what Morrison was writing, while Diana was two completely different characters under Azz and Jonhs.
As DiDio pointed out, under these circumstances, and with multiple interpretations of the same characters running around, it was impossible to make a shared universe work. And DC-You's loose continuity certainly didn't help.
The SM/WW relationship was probably one of the few (if not the only
) things that had a sort of planning. After DC's higher-ups discussed the idea with Mrs. DC Entertainment (D. Nelson) to know her professional opinion on it and received her and WB approval to proceed, they began mapping and planning for two years (2010/2012) the ramifications and repercussions that the relationship would have had in the wide DCU.
Examples of said "repercussion" in the published stories are Amanda Waller creating her own JLA among many reasons to prevent SM/WW from procreating (or something like that
), the subplot of Booster Gold disappearing in the JLI Annual and Diana/Clark's relationship leaking to the public in SM/WW.
As it was said, the idea was to open new narrative potential for DC's various editors and writers and expand DC mythology.
On the character side, it was established that Diana and Clark didn't know each other outside of superheroics, and the beginning of their relationship would make them compare with their different backgrounds and learn from each other.
Johns: "How do they affect one another? They're similar in many ways, but they're very, very different in a lot of ways and they both have different viewpoints and different upbringings and dfferent M.O.s, so to see those two come together is going to be some great storytelling."
In-story examples: in Johns' JL we see Clark bringing Diana to Smallville to show where he group up, letting her start to know him better and giving her the idea of using a secret identity as he does, in Soule's SM/WW is Diana influencing Clark to be more open about who he really is, etc...
During Doomed, there's a moment when Diana looks for Clark and among all places she doesn't think to looking in his Metropolis' apartment, showing that she hasn't become yet familiar with Clark's lifestyle. On this, Berganza explained that they're still in the "early stage" of their relationship so they still don't know each other well.
It's a shame that due to DC's general chaos at the time and the constant crossovers, this characters development has been constantly delayed and then came Convergence... (I'll PM you about that later)
So much set-up and no pay-off.
Some sources about what I wrote:
http://usatoday30.usatoday.com/life/...ook/57328804/1
http://www.cbsnews.com/news/superman...or-first-time/
http://ew.com/article/2012/08/22/jus...-12-exclusive/
There are also Soule/Tomasi's interviews that say a few things I reported. The stories also speak for themselves.