As TV viewers increasingly move to online programming sources such as Netflix, Hulu, and Acorn Video, two major players in the cable/satellite TV world are contemplating selling online subscriptions to customers who don’t have cable or satellite service. If this happens, which is by no means ensured to occur any time soon, it would be a serious game-changer in the television industry.

Separate comments today by Jeff Bewkes of HBO owner Time/Warner and Les Moonves of Showtime parent CBS suggest the two companies are seriously considering an end-run around the cab/sat providers by selling their wares directly to consumers over the Internet.

Deadline.com reports that both HBO and Showtime are experimenting with direct-to-consumer options, and their parent companies seem increasingly unafraid of incurring the ire of the cable and satellite companies that currently distribute the channels. Any move of these two giants into direct-to-consumer distribution would be a huge blow to the cable and satellite companies, who are burdened by rapidly increasing fees charged by major program providers such as Disney Co. (for ESPN and its other sports channels), Viacom, and the TV networks. Higher costs and the same or reduced value of products constitutes a recipe for business decline.

An interesting angle: CBS owns Showtime, and CBS benefits greatly from the user fees the cable and satellite distributors pay for rebroadcasting the CBS affiliates and CBS’s other cab/sat outlets. How much CBS is willing to risk that relationship will tell us a good deal about the future of the cable and satellite industry. In any case, current signs are that the exodus of customers from cable and satellite systems will only increase in the months to come.