The Guardian today had a picture of Bradley Wiggins today "back on the road" dressed completely in black, albeit with a yellow helmet (like pic below). You'd think he'd wear something a bit more visible, particularly as he's bound to cycle fast.
I've cycled to work 3 times this week and always wear a high-vis jacket and flashing lights if it's dim or misty. I normally amble along too, in no rush to get to work. Cycling after dark can be pretty scary, and I often take a longer route that avoids dangerous roads and junctions, or has more streetlights.