I run a Sanyo dynohub on my commuter, same as post 18 above. Very pleased, and would not go back. The light was the cheapest dyno light available at the time, maybe $35. Taillight was about the same. I run a Shutter Precision dynohub on my rando bike, which sees all night riding. That lighting system cost about 3x as much. Previously I had a Shimano hub, but sold that bike.
I lock my my wheel to discourage theft, mostly because I don't want to walk home.
Lights and batteries keep improving, so I won't say "never", but the forget-it nature of dynohub lighting is worth lots. For randonneuring, no contest.