I really enjoyed the first issue, though it definitely felt like an introduction to a 12 issue maxi.
My favorite parts were the Joker/Selina old colleague, fellow professionals dialogues. Like Dixon and Dini and some others, King can really get at Joker,, of subverting your expectations with him in a humorous or surprising or even tender way. There's a great bit of a nod to LOTDK Going Sane as far as Joker.
And as for Andrea Beaumont, King does her and Mask of the Phantasm respectfully as far as this introduction. With Mask of the Phantasm perhaps being the ultimate Batman love story, all these characters together here feel right if you're gonna take another stab at a statement on the subject of Batman and love.
Clay Mann rocked, his zoot suit Michael Jacksonesque Joker really wowed me.