It will be months before the “Battlestar Galactica” prequel will air -- at last report, the series launches “sometime in 2010” -- but now you can watch the two-hour first episode, out on DVD and digital download. Be aware that the wait will be agonizing after this first disturbing taste of “Caprica” as apocalypse creeps forth. Bonus: This version you buy is unlikely to premiere on TV. It’s a hard R right off the bat. (Tuesday)
