Okay, this is spoilerish, but rumors abound that it will likely change anyway, if this plot is true.
This is what Singer pitched to Warner Bros.:
Lex makes a deal with Braniac, bascially handing over his entire company to the super villain (and one would assume, himself) and havoc ensues. Apparently the son is involved, too.
Other than the son issue, this sounds suspiciously like Kevin Smith's unused Superman Lives/Reborn draft that Tim Burton was to direct and Nic Cage was to star, back in 1998. It had Supes dying, Lex and Braniac (plus Doomsday, I think), a giant robot spider (put into Wild Wild West instead, seriously) and a gay robot (seriously--producer Jon Peters liked the gay character from Smith's Chasing Amy). You can read about the zaniness, like Braniac's space dog, over at IGN.
I think if they saved this for part three, I'd be okay with it, maybe have some gigantic villain that Supes can go mano a mano with.
What do you all think?