If we're talking about a commuter bike, a dedicated workhorse bike that you're going to ride every day, irrespective of weather, daylight, etc, I don't see how you can get by without dynamo lights. Mine have been in place since I put this bike together about three years ago, and in that time they have not required any attention from me. If the wheels are turning, the lights are on. I've had flat tires, replaced the chain, changed the crank, lots of minor repairs. But the dynamo lights are just there.
I'm all for redundancy, blinkies, rechargeables, whatever. And I'm all for commuting on a different bike every now and then, maybe even a bike without a dynamo light; that's what I have the blinkies and the rechargeables for. But if you're serious about commuting by bike, I just don't see how you can get by without dynamo lights.