Jay Leno tonight took again on his favorite joke target, NBC, mocking the chances for reconciliation with the network. “Before we get started, let me say that NBC and I have reached a peaceful, amicable agreement that will be beneficial to both sides… April Fools! It will never happen,” Leno said in his opening monologue. Also today, April 1, the embattled Tonight Show host put up an united front with his anointed successor, Jimmy Fallon, filming a Late Night promo with Fallon that riffs on the NBC late-night controversy.