Information on the pitch and idea for the city here.
SPOILER-ish thoughts beneath the cut
Minor edit once I realized who they were talking about at the end.
Yeah all the copper in the city, especially the lid in the fountain, pretty much confirm my suspicion where this story is headed. That for whatever reason--by accident or intention--Ras built his city of killers over the pool of dark mystic energy that created the Untitled. We know that Ducra knew the Al Ghuls well and that Jason was the last student of the All Caste. Copper is the only known weakness of the Untitled and well Jason is the only one (besides the apparently retconned killing Essence did) to slay any of them.
Is Constantine still bisexual in the new 52? Because December seems like he's inclined that way so their history could have another meaning.
Good ideas for the League of Assassins but I'm still not convinced with how this ties in with Jason. Of course any connection between the character and Morrisons' work is worrying.
Sometimes I think of Cassandra Cain as more of a bat character than LOA. Mentioned her makes me cringe because...well anything that links her with the league isn't great after OYL. I get the feeling if she was shown under Tynion (although it very well could be someone else) she'd be written as an assassin again or someone the LOA want to hook up with Jason since Ras was all about legacies.