Originally posted by Liberator-9000:

If I have to guess, it's why you can see Johnny Silverhand and that he is immortal via the means of the chip.

This has been confirmed in trailers. It also fits in with the actual novels on CP2020. There is a lot of respect given to the original lore (though there are differences too, like the voodoo boys not being a bunch of white wanna-bes). Alt Cunningham (Silverhands in universe girlfriend in 2020) is the original programmer of soul killer. Which serves as the basis for our chip in 2070. Saburo Arasaka, CEO of the most powerful megacorp Arasaka Industries, ends up kidnapping her and refining the program.

Soulkiller in the original story basically copies the users personality and knowledge, then 'erases' the brain leaving a husk. In this way a ghost in the shell-esque immortality could be achieved.

Obviously this does not translate 100% into the game, but its interesting to see some divergent results already.