My front wheel was vibrating a bit and any time you feel an unusual vibration or noise on a bicycle it's a good idea to stop and take a look. (This is one reason I like my bicycle to be silent.)
Turns out there was some additional friction in my front hub caused by a pitted cone. Larry, from whom I bought my bicycle, offers free wheel service for wheels built by him. He replaced my cone for free.
As I'm nearing (over?) 1,500 miles, I suspect more and more things will be wearing out, though pits in the cones could have been from a manufacturing defect or bad assembly or adjustment. For a car 3,000 means just an oil change, for a bicycle at 6,000 it might mean an overhaul.