Last night featured three premieres, but to put things in perspective, let’s start off by saying that a repeat of Family Guy on Fox (1.5/4) was the No. 1 program of the night among adults 18-49. An American Dad rerun (1.4/4) was No. 2. Now to the newcomers, none of whom made an impact as the broadcast networks’ summer is still looking for a breakout. ABC’s Celebrity Wife Swap (1.3/4) returned to the schedule down 19% from its last original on Tuesday this past spring. It was followed by the debut of Whodunnit (1.3/4), the new unscripted mystery series from CSI creator Anthony Zuiker. That was a soft number but, given the lackluster performances this summer, it actually tied Fox’s Does Someone Have To Go? as the highest-rated reality debut. NBC’s drama acquisition Crossing Lines managed a 0.7/2 for its two-hour premiere. It was down from the recent openers of ABC’s Motive and Mistresses (1.2) and tied another NBC import, last summer’s Saving Hope, as the lowest drama debut on a Big 4 network ever. Tonight is CBS’ turn to try and beat the summer doldrums with Under The Dome.