>>>http://i.imgur.com/W2r0y.jpg
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>>My first thought it was faked, the lighting doesn't look consistent, but it seems it's real:
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>>http://www.washingtonpost.com/national/health-science/dust-storm-sweeps-through-arizona/2011/07/06/gIQATWc8zH_gallery.html#photo=1
>
>Not an expert on photography but it looks like the photographer used a wide-angle lens as the buildings and shapes on the outside of the picture lean inwards towards the center. This creates an effect which might make us feel the photo has been faked or adjusted perhaps?

For sure it's a wide-angle shot, that helps give the cloud a "looming" effect. The image quality is decent in the middle (e.g. antenna tower) but drops a lot out to the edges, for example you can hardly read the Wells Fargo sign to the right on top of the office tower. Implies a low-quality lens, low pixel count sensor, small sensor size, or all three.

Although there is some ambient light, there are significant pools of light under each street lamp. Implies either dusk or dawn. I can't tell if it's dawn with the storm approaching from the east, or dusk with the storm approaching from the west. Could probably figure it out with Google Street View and a little time, maybe even figure out the exact location of the photographer.

Flash is impossible for a large scene like this so to get decent exposure the ISO may have been cranked up and/or a large aperture selected, both of which would reduce image quality. Even with all that the final image was probably darker than what we see here. I suspect the brightness/gamma of the image were adjusted afterwards.

Superficially it doesn't look like a long exposure was used, there are few vehicles on the streets but I don't see any motion blur, and the storm clouds show some detail that might get blurred with a long exposure. Not seeing any overall blurring due to motion during the exposure.