Thile has hosted quite a few shows when Keillor has had time off. He's delivered an opening talk and participated in a few sketches, but far more than Keillor he's largely done music.
By the way, I liked the choice of songs here for another reason, other than it being appropriate. Back at Northwestern, I had several radio shows on the campus station WNUR, and a couple of them were folk and a sort of menagerie of styles (cleverly titled, Potpourri). And I ended them both with a recording by The Weavers of..."Gotta Travel On."