"Spinal Tap" is a great film, and I've kept up with all or most of Christopher Guest's mocumentaries over the years.
They were being interviewed last night on Tavis Smiley as themselves, not in character. Either this was a piece of brilliant performance art, and they were satirizing themselves and the Hollywood establishment, or these are three of the most pompous guys you've ever seen.
Actually, Michael McKean came off OK, but Guest and Shearer came off as totally pretentious windbags.
My favorite line of the evening was when Shearer said, and I'm paraphrasing, "The best thing about this tour is that we're playing the songs as ourselves. When we played those Spinal Tap songs for the movie, we were approaching those songs as the characters would. Now, we're playing them as ourselves, so we can make different artistic choices." Keep in mind that he's discussing songs about Satan, Stonehenge, and girls with fat asses.
If this appearance was intended as promotion for their tour, I wouldn't go.