The Cable Companies are waiting for the NFL Network to offer a small % of ownership to them, and they will include it as a basic channel. Such is the case with most free TV Cable stations.
I get NFL on Dish Network as part of my sports package, which includes all the regional networks (FS New England and New York, NESN, MSG, SNY) as well as the horse racing stations, golf and tennis networks, and alot of soccer. Costs me 6.95 a month. When i had Comcast, the sports package was 12.95, and that was only basically for speed channel and some filler junk.