Yeah, many possibilities. And if at E3, maybe just tidbits.
It is set in an open world metropolis called Night City, whose inhabitants communicate in non-English languages. Players who do not speak the languages can buy translator implants to better comprehend them; depending on the advancement of the implants, the quality of translations will vary, with more expensive implants rendering more accurate translations.
Hmm. Not too many games have "that", meaning alternative, unique dialogue...
I believe the most extensive ones are Arcanum (Intelligence 5+ vs <5) and VTM Bloodlines (the "insane" Malkavian clan - very different from the rest of the clans). Both were made by ex- Fallout 1 & 2 devs*, as *Obsidian carried on in New Vegas. Altho the others relevantly scale a bit and have good moments, VTMB is arguably best with (much) more dialogue that, while less reactive or consequential, has cleverer exposition and better acting. I'm unaware of other games as extensive (well, except this, lol). Bioware attempted dumbspeak in NWN1 but it's only our character's text, no responses from any NPCs AFAIK, and they ditched it in the expansions.. Obsidian didn't do it in NWN2, tho decently a few years later (not on F1&2's levels, yet closer to them than F3; F2's is the best of those, and Arcanum is a notch or two above F2, IIRC). (Edit: This paragraph is sloppy, as it's been several years since I played some of them, and my struggle/laziness to find good comparison vids).
Put such stuff with a different class/style, good C&C, some bacon, etc., and I got me another great playthrough. I'm not forgetting the rest, like the Nosferatu clan's ugliness (which a lot of NPCs react to), Silver Shroud, or
Overseer First Citizen Lynette's dialogue mechanics - the latter mentioned by a CDPR guy in an old article I failed to dig up. And I realise this feature could be very different, possibly even better. Also possible that development might be stretched, making this too shallow (less interaction, more background fluff), or it'll be ditched.
Wait. What about language localisation? Would they swap languages around for certain regions? Or make it so we can customise, maybe 1) main language 2) foreign NPCs'? The latter could be unified to 1 or 2 languages to make it "easier". Or would CDPR use and expand Witcher's semi-fake languages instead? My point is that it'd be dumb for players to understand a language while the text shows otherwise. However, it could be a logistical nightmare or a feature they simply don't want, so I shouldn't get hyped...