I guess that one of the most common reasons people say that they want to shoot in black and white today is because it lends a certain timeless quality to the images. Is this because we still think of black and white as being a throwback to the photographic past?  Back in the old film days I reckon that 50% of my work was in black & white, because it had to be.  These days it comes down to personal preference and there IS something about a good street image or a highly graphical composition or even a portrait that just looks so much better in monochrome don't you think?