I agree with Russ that modern sensors with their greater dynamic range have rendered the use of ETTR moot. That said, I can envision a shot — street scene at night, no highlights, just blacks and grays — where overexposing the capture and reducing the exposure in post processing gives a greater latitude to make adjustments. It gives a cushion, more data to be manipulated.
But truth be told, with my D3s I rarely do this anymore.
Jon Kandel A New York City Nikonian and Team Member Please visit my website and critique the images!