I can understand why you people can be a little put off with running in the dark, I combat this with running along well populated routes (houses and businesses) and taking my phone with GPS and my music on. I only wear one ear piece and have the music or audio book quite low so I can hear what is still going on around me. Also everyone knows that murders and kidnappers don't get up till lunchtime!
The other thing is to try and go out for a early morning run it gets lighter while you run, rather than darker. I am member of a club and go to club night at least once a week. I have encouraged a number of work friends to take up running and we often use it as a excuse to get out of the office on time and run together. Last year we went out in the rain and the snow the trick is to concentrate more. and watch what you are doing 
As for the cold, I mainly wear a long sleeve top, t-shirt over that, then something vaguely waterproof as a final layer and long running tights. For head wear usually a beanie hat and gloves which I normally take off after 15-20 minutes (too hot!)
Edited: 06/10/2011 at 22:21