Hardware Secrets posted a review on the iPod Nano Mono-Chromatic

Forget about the last iPod Nano: this newborn fourth-generation is the one that Apple fans have been waiting for since the launch of the sleek and skinny second-generation model, which had colorful display, capacity for photos and a great design, but yet played no videos. The third-generation, launched on September 2007, had finally brought videos to the Nano, but had disappointed on account of its wider body design. Now, Apple has brought together the evolution of last year's third-generation with an improvement on that slender and ‘old-style' design.

iPod Nano Mono-Chromatic Review