Comcast reports its fourth-quarter earnings before the bell on Thursday. Wall Street will be paying close attention to the state of the company's broadband business, as well as any progress of the spinout of its cable TV networks.Comcast's broadband business has been the focus for Wall Street for some time now, as customer growth has been in the midst of an ongoing slump. Last month Comcast Cable CEO Dave Watson told investors the company expected to lose more than 100,000 broadband customers during the fou ...