For once, the AP’s reporting is spot on: It is indeed an instant classic. He’s either stoned out of his gourd, in the grip of a slow-motion nervous breakdown, or a better actor than we thought. Even more entertaining than the legendary Merry Miller/Holly Hunter meltdown, although that’s because Letterman’s in unusually good form. Exit question: Farrah Fawcett-esque freakout or Andy Kaufman-esque hoax?