Personal preference here, but I thought the Western 'feel' of the books was intrinsic to the character of the gunslinger, and the success of the story overall. He represented a character type we all identify with; the strong, noble, skilled and deadly gunslinger as seen in many classic Westerns, and often made iconic by the likes of Clint Eastwood. Cliched it may be, but I always felt his integrity, values, style and even dress sense - dropped into a universe of parallel worlds, strange creatures and a huge quest - were what made the books unique and quite memorable. And when he is transported to modern day Earth, he stands out like a sore thumb.
He is simultaneously a caricature of an old and ancient world - where good and evil are very simple black and white concepts - but also a symbol of goodness that people in the modern world would aspire to be, muddled as we are by all the grey areas we face nowadays.
If they lose that Western feel and make this a more modern telling, I think some of the magic of the original story will be lost in that translation. But I'll reserve judgement till I see it.
