NEW YORK (AP) — More than 32 years of late-night talk will pass into history next May 20, with CBS’ announcement Wednesday that David Letterman will host his final “Late Show” on that day. If Letterman makes all of his scheduled broadcasts until then, CBS said he will have hosted 6,028 versions of the “Late Show” and its NBC predecessor, “Late Night.” Letterman moved to CBS in 1993.