I was wondering the same thing. This is from their Q&A section on their web site:
"Q: Will Circuit City match its own prices?
A: Yes, if you purchase an item from us (in-store or on circuitcity.com) and we advertise the same item at a lower price within thirty days of your purchase, we will refund you 100% of the price difference. Bring the advertisement and your original sales receipt to your local Circuit City for the refund."
I would think that they would have to honor the price difference, but I imagine they would fight you on it. I was wondering if anyone has everyone done that before.