Use of winter (studded) tires on only one wheel? Does anyone have any thoughts on use of winter (studded) tires, such as the Schwalbe Marathon Winter tires, on only the front or rear wheel (and with a standard tire on the other wheel)?

One winter tire is better than none if you're going to be riding in snowy conditions, so go ahead and throw it on. If you do end up running only one tire, you'll probably want it on the front wheel so you don't lose traction while cornering and so that you can maximize braking performance.