You seem to have, again, missed one important bit of information about the setting. You keep saying that HR's setting has nothing to do with the first game when plenty people (myself included) have pointed out that it's a prequel - that's the official line, the events of the game will lead to the founding of UNATCO, the anti-terrorist organisation JC Denton worked for in the first game.
As for the Tokyo-ish look? If you're referring to that city that looks like it's got two layers to it (and most of the trailers appear to have been set there), according to the Deus Ex wiki, that's Heng Sha; a densely populated island off the coast of Shanghai.
http://deusex.wikia.com/wiki/Heng_Sha
Detroit, on the other hand, looks pretty much like a modern-day city: http://deusex.wikia.com/wiki/Detroit
EDIT: I also found this on the Deus Ex wiki that gives a bit more info on the Renaissance look of the game:
"The pace of technological development is reflected visually by a Renaissance theme. Characters who support the advances of human augmentation dress themselves and decorate their homes in reinterpreted late-mediaeval Italian style, and the game as a whole has a sepia-tinted colour palette reminiscent of historic manuscripts. In contrast, characters who oppose augmentation wear clothing that is more or less current-day. "
As for the Tokyo-ish look? If you're referring to that city that looks like it's got two layers to it (and most of the trailers appear to have been set there), according to the Deus Ex wiki, that's Heng Sha; a densely populated island off the coast of Shanghai.
http://deusex.wikia.com/wiki/Heng_Sha
Detroit, on the other hand, looks pretty much like a modern-day city: http://deusex.wikia.com/wiki/Detroit
EDIT: I also found this on the Deus Ex wiki that gives a bit more info on the Renaissance look of the game:
"The pace of technological development is reflected visually by a Renaissance theme. Characters who support the advances of human augmentation dress themselves and decorate their homes in reinterpreted late-mediaeval Italian style, and the game as a whole has a sepia-tinted colour palette reminiscent of historic manuscripts. In contrast, characters who oppose augmentation wear clothing that is more or less current-day. "