Lemire has also said he was bringing in someone from Frankenstein: Agent of SHADE. My assumption was that it HAD to be Ray Palmer, but perhaps it's Frankenstein himself... Lemire used him in Animal Man after all.
If they announced Ray Palmer, I would believe it. I would assume that he would take the Atom mantle, which would make sense since both Hawkman and Green Arrow are on the team. But still, the confirmed people so far are Adam Strange, the First Nations girl, Hawkman, Green Arrow, and Animal Man.
I would be super happy if Atom made the cut. I would be far happier if Black Canary was announced, too.
And that's not all. One more member of the Justice League of America has been confirmed. But I'm not too sure who it's going to be. For the record, the candidates are J'onn (most likely), Selina, Tatsu, Simon, Cisco, and Courtney. If only Jeff Lemire could give us a hint.