It would have to be damn cold for me to do a vapor barrier in my shoes while running. I use them in the winter while mtb'ing, but that's because my clipless shoes are extremely ventilated and the speeds are higher so my feet get cold as hell. While running, I've never had that problem, even running down to -4F. I don't tend to run through much standing snow though.
Depending upon how cold it is, you may want something to cover your mouth that you can breathe through readily. It will soften that cold air a bit on your lungs.
Personally, I tend to have more troubles with overheating than anything else, but a big piece of the puzzle for gear, as others have noted, is the sort of location you're planning on running. The more isolated, the more ready for weather changes you need to be, so the more you'll carry. If it's not terribly isolated, I'll wear a silkweight ls capilene, lightweight beanie, liner gloves and shorts. This suits me down to about 30F if the sun is out. If it's overcast or breezy Istep up the thickness of my ls because that will still breathe well, and I may don tights. If I'm getting a bit off the beaten track, but not too far, I carry a lightweight softshell which I can strap to my Camelbak. I have the older version of http://shop.camelbak.com/2012-ultra-lr-vest/d/1070_c_131_cl_585
which doesn't move at all and isn't annoying to run with.