In what is the comedy equivalent of Death Cab For Cutie covering a Decemberists song, or perhaps a tote bag fashioned from a vintage cardigan, Portlandia star Fred Armisen will co-host this week's episode of This American Life while impersonating Ira Glass, thus ending years of speculation that Ira Glass actually is a Fred Armisen character. The show will be themed around doppelgangers, that utilitarian German word meaning "two guys who wear glasses talking to other people who wear glasses," and thus provides Armisen the opportunity to debut the Ira Glass impersonation he once worked up for Saturday Night Live but ultimately scrapped, after it was decided that Ira Glass isn't famous enough to spoof—at least not on SNL. "But Fred, Ira Glass isn't black," Lorne Michaels probably also said.