I'd go with b&w, but in this example the faces are way too dark for my taste - what's street photography without strong faces (like that sneering guy third from the left)? If you're using Photoshop's or Aperture's Black & White adjustments, I'd dial-back a bit on the red slider.
Overall? There is no rule of thumb when it comes to b&w vs. color (regardless of subject matter), any more than there is for exposure, contrast, saturation... Isn't it all about capturing our personal vision, so that it can be shared with others?
But it's also strongly about our personal influences. I think a fair part of the reason we lean towards b&w for street photography is accident - it's the medium that was used by Matthew Brady, Cartier-Bresson, Weegee, Dorothea Lange, et. al. Contrary to the familiar saying, those who study the past are doomed to repeat it - the artists we admire become our personal benchmarks.
I wonder where we'd be today if an affordable, easy-to-use color process had been invented in 1840, and if there was little incremental cost to producing print publications in color?