Katie Couric might end up back on the “Today” show when her “CBS Evening News” contract expires at the end of May. A spot will be open because Meredith Vieira is expected to leave “Today” to spend more time with her family. Sources say Couric had been talking with her old friend Jeff Zucker, her producer at “Today” before he rose to CEO of NBC-Universal. But Zucker’s just-announced exit from the network won’t preclude a Couric move to NBC. She’s also lunched with Time Warner chairman Jeff Bewkes, whose empire includes CNN. Sources also say she gets along famously with CBS boss Les Moonves and might stay with the Tiffany Network, although for a much lower paycheck than the $15 million a year she’s said to be making now.