Again guys, thanks for all the advice.
I'm looking to stay under $1000. The way I see it, I can make up that much money on gas alone in one year. So, I view this more as an investment (both financially and health-wise) than a financial burden. Still, I psychologically have problems with purchases too large.
Before I make large purchases, I like to do as much research as I can. I am thus still doing a lot of reading about components, etc.
It appears that my commute will be more like 5-10 miles each way. Potholes will be present, but not devestatingly so. I would like to have the best cruising speed I can, so I'm still interested in the road bike, though I did look at some cyclocrosses as y'all suggested. For something like the Trek 1200C, would I be able to put "snow" tires on it in the winter? Also, how much snow is reasonable to safely ride in? What other modifications should I consider?
One final question: What is a tube? Everyone talks about tubes, but I have no idea what they are referring to.
Thanks.