Art is correct about Tony Seeger. He left Smithsonian Folkways and moved on to UCLA as an academic ethnomusicologist. I assume he's still there, but have no knowledge one way or the other.
Sadly, Ewan's daughter Kirsty MacColl (not a Seeger), was killed in December 2000. She was swimming off the coast of Mexico when she was hit by a speedboat which, as I understood things, was in an area reserved for swimmers. Her two children were with her, but were not hurt. It's one of those really ghastly stories. Kirsty had a number of pop hits and had recorded the CD Tropical Brainstorm, influenced by Cuban music and very much a pop record, shortly before her death.