Details given to us last night about Valve's rumored casting of the sequel (or prequel) to its Orange Box hit Portal hinted at a big role for Aperture Science's founder Cave Johnson. The potentially spoiler-iffic painted portrait and brief bio of the possible Portal 2 antagonist led us to believe that the sequel may take place prior to the original. Maybe not, based on some rumored dialogue that a source passed on.
Warning: It's all spoiler territory from here on...
The script samples we saw for the Cave Johnson role indicate that the Aperture CEO and "eccentric dead billionaire" is, well, already dead, living on in simulated computer form. He tells an unnamed rookie test subject via loudspeaker that "As of this mornin' yer old buddy Cave has been resurrected inside of a computer. And I never felt better!" acting as this entry's GlaDOS—possibly that prototypical GlaDOS, as theorized earlier—encouraging the player to continue the testing while waxing philosophical about the afterlife.
"I been thinkin," the script reads, "Heck, suspended as I am in this inky purgatorium, I got nothin' to do but think. What if them engineers didn't do me no favors pourin' me into a computer? What if they denied me my final reward?"
No telling if this internal conflict is the catalyst for Johnson "[losing] his grip on humanity as the story progresses" but if things go wonderfully wrong as they did in the first, it would certainly make for a compelling narrative.