It's doubtful we'll see him anytime soon (if ever). I seriously doubt WB has enough backbone to use a villain like him.
I know what i'd do.
I'd have Brainiac as the main villain in a reboot, with Lex in the background.
It would be discovered about midway through the film after a couple of confrontations between superman and brainiac, that brainiac is really working under someone else, someone even more powerful than he. Brainiac was sent to test the Earths defenses for an invasion.
We never really see who it is giving brainiac orders, but we hear his voice. A deep, booming voice.
At the end of the film, after Brainiac is finally defeated, we get to see who it is that we have been hearing. we see a large figure cloaked in shadow sitting on a throne on a distant, fiery, planet. We only see his outline, everthing else is dark. He looks up and all we see are two eyes glowing white in the darkness.
Motion capture with a blend of live action. voice, either Michael Ironside or Michael clarke Duncan.