While it certainly does not appear likely that CBS will renew the ratings-plagued Swingtown, Broadcasting and Cable is reporting that CBS Paramount (the production company, not the network) is shopping the show to cable networks.
Clearly the CBS network wasn't happy with the ratings, and moving it to Friday nights, where it's ratings have languished even further seemed to indicate CBS didn't have high hopes for the show. Additionally, CBS entertainment president Nina Tassler is on record about being disappointed in the show's ratings.
CBS Paramount is additionally, according to the B & C story has also contacted DirecTV.
I know there are a lot of fans of the show, but it never took off and actually shed viewers from earlier episodes where it performed very well. It's unfair really to compare Swingtown to to Jericho or Moonlght, because Swingtown aired in the summer, but it seems unlikely to me that a cable network will pick up the show or that CBS would do any kind of partnership with DirecTV as has happened with NBC and Friday Night Lights.
It seems like the CBS owned Showtime would make the most sense if there is interest in picking the show up, and that would allow it to be more true to its subject matter creatively as well. But if CBS wanted to move the show to Showtime, why not just do it? Announcing that you're shopping the show to multiple outlets seems to (but does not necessarily) indicate the Showtime route is at best perceived as a last resort.