SEASON PREMIERE: I always get a little wistful when the season premiere of SNL approaches. Not because I’m all choked up at a show that’s now starting Season 39 – but because the original premiere of Saturday Night Live, way back in 1975, marked my first published newspaper column as a professional TV critic. So if SNL has been plugging along for nearly 40 years, welll, so have I. And for this year’s show, which has lots of cast changes afoot, the guest host is the program’s former head writer and star, Tina Fey. Musical guest: Arcade Fire.