Showtime announced another comedians-talk-comedy interview series today: Laughing Stock, from executive producer Steve Carell, will feature comedian David Steinberg conducting one-on-one interviews with the likes of Mel Brooks, Jerry Seinfeld, and Tina Fey. Showtime already has The Green Room With Paul Provenza (which should be better than it actually is) and HBO just aired its Talking Funny special, though both pale in comparison to the current comedy-interview gold standard, "WTF With Marc Maron." Steinberg already did a similar series, Sit Down Comedy, for TV Land from 2005 to 2007. How many more pull-back-the-curtain-on-comedy shows can culture sustain? Eh, probably a few more.