The popularity of road bikes in your area will have an effect on its selling price. So to will the frame size. Bikes that are of average size (e.g., 54, 56, 58) will be slightly more marketable than will bikes for exceptionally large or small people.
Your bike had a MSRP of $689. Trek's '09 entry level road bike (1.2) listed for $879 and is being sold at discount to make room for '10 models. I understand buyers have paid as little as $700 for the remaining 1.2s. In my market, I'd probably list your bike for $450 and be willing to take $400. There is, however, strong interest in cycling in my area.
If your market isn't as strong, you could take a chance on a no reserve auction listing on ebay. Let the bidders run it up. Given the condition and the fact that you'll be drawing competing interest from all regions of the country, the price could be very good. Of course, you'll have to deal with shipping it and work the charges out with the buyer.