ShowtimePremium cable network Showtime has added some of their library of entertainment to the iTunes Music Store. Alert reader Ruben discovered this last night while I was fast asleep. The new television shows that they’ve added are Sleeper Cell, Weeds and Fat Actress, the reality/comedy from Kirstie Alley.

Two things that are especially interesting are in play here. One, this is the first of the premium cable networks to offer their ware on iTMS. Because these programs already air commercial-free and for a premium from their customers, I was wondering if the opportunity to sell them piecemeal through iTunes would be enough of a value proposition for these networks. Apparently it is.

Secondly, and perhaps even more importantly, Showtime is owned by CBS Corporation. Does this mean that CBS could be joining the iTunes fold soon? It certainly means that negotiations are already coming to some sort of fruition.