Riding with the flow of traffic, imho, ignores the increasingly significant risk that inattentive automobile drivers pose. eg: distracted by cell phones, texting, adjusting radios, swatting kids in the back seat, reading a map, finishing lunch, putting out a cigarette etc. etc.
None of the above scenarios improve your odds of being seen, but rather increase the odds of getting run over. It's interesting to me that the law suggests that pedestrians walk against the traffic, but not for cyclists. Your "profile" or "visual footprint," whether cycling or walking is approximately the same size when the motorist sees you. And, the argument for a "closure rate differential" disadvantage riding against the traffic, with the possible exception of residential areas with 25mph limits, is negligible.
It's widely accepted that motorcycles are difficult for motorists to see, notwithstanding being larger than cyclists and utilize day-time running lights. However, contributing factors frequently cited for car/motorcycle accidents is that the motorist didn't see the motorcycle.
Darwinian or not, until I grow eyes in the back of my head I'll take my chances riding against the traffic. Having the opportunity to observe the potential threat as it approaches, and thus having a chance to avoid getting hit certainly seems to be better odds than just crossing my fingers, hoping for the best, and letting everyone else determine my fate.