Comcast (like all cable companies) uses fiber optic cable for it's infrastructure. Fiber goes to the local node (FTTN), and from there you get coax to the individual residence. If it is Comcast that is laying cable right now, it is for replacing the original copper infrastructure that Time Warner built when they built this market out, before Comcast bought the market from them. The goal of the upgrade is to enable the use of DOCSIS 3.0, which is the current revision of the cable modem spec and will enable transfer rates of 100mbits/sec and beyond (though I sincerely doubt that the initially available bandwidth plans will offer such speeds). The current infrastructure only supports DOCSIS 1.0, which is why the fastest we can get right now in Shreveport is 12mbits/sec. Over in Bossier, where Suddenlink has the cable franchise, DOCSIS 3.0 was implemented in early 2010, which is the reason why people there can get plans that offer 50mbits/sec. Comcast has already deployed DOCSIS 3.0 networks in many/most of it's markets; Shreveport just lags behind because of the cost of the project due to the size of the market combined with the age of the assets currently in place. The good news is that once DOCSIS 3.0-based plans are available, we should see much more bandwidth for much less money (per mbit/sec) than we currently pay.

If it turns out that it is AT&T laying the cable, then it is in fact likely that it is to support their U-Verse service, which is similar to cable in that it is also a fiber-to-the-node model, except that instead of coax from the node to the residence, it's ADSL from the node to the residence. In my long and unpleasant relationship with both AT&T and ADSL independently, neither has proven to be an enjoyable or even satisfactory experience. The rate plans for U-Verse are similar to that of traditional residential ADSL; not positioned very well at all to compete with new fiber-fueled cable networks and FTTH deployments such as Verizon FiOS.

As for Verizon FiOS, we will likely never see that service in this area, since Verizon has no franchise rights in the state of Louisiana for anything except wireless service - they even use AT&T for their wireless network's backhaul here.