Hi Julie,
I'm more or less in the less is more

camp when it comes to dressing for winter running. After a couple of miles your body generates plenty of heat, and I think at that point a lot of runners end up overdressed. So then you sweat more, get wet, and then you'll just get colder. At least that's how it goes for me; I sweat a lot more than most people, though.
A couple of wicking layers is usually the most that I'll wear outside, unless it's windy AND very cold (say, below 20). Below 30 I'll usually tack on a hat and maybe gloves.
Lately when undecided, I've leaned more toward adding the gloves and hat over adding another body layer. Having a warm head and hands seems to make the cold much more tolerable. I wouldn't mind trying those arm sleeve only things sometime. Whatever the case, stay away from the cotton if you'll be outside for any length of time at all, but you probably know that already.
When racing I'll get downright skimp. Not quite at Ron Black's level (shirtless in January!), but usually just a shirt and shorts.
I'd love to get some yak trax someday, but I'm not sure if I'd get all that much use out of them around here.