I'm considering switching the commuter to dynamo for the winter, bloody expensive though.
Hubs should last a long time (my last one - a Shimano DH-380- did about 25,000 miles before it developed a bit of play in the bearings), I've had my front light, a B&M IQ Cyo since 2009 and it still works fine. Total cost in 2009 was about £180 including wheelbuilding labour cost. I also had the wheel rebuilt with a new rim at some point but that would have been the case with a regular hub too.
Both light and hubs used in all weather, actually especially in bad weather as I tended to use other bikes if it was dry and sunny.