I have a B&W version of this shot on my Facebook page and after lots of great feedback from so many of you, I decided to go with the color version after all.
The 120 second exposure was achieved using a 10 stop B+W ND filter. The resulting image is a single exposure, no bracketing or HDR. Editing was done in Photoshop CS6 and Nik Color Efex. Editing primarily involved removing distracting elements, color grading, dodging and burning and selective sharpening through various high pass layers.
Thank you for looking!