I found one site that listed
What happened to the castaways of 2000...
Tanya Cheadle, 34
The camerawoman fell in love with Castaway's assistant director, Paul Overton. They married three years ago on Taransay beach and have a son, Tomas, nearly two, and another child due in May. The couple, who live in Glasgow, made a series about a children's hospital in Chicago.
Ron Copsey, 50
Castaway viewers remember Copsey burying his beloved border collie, Charlie, on the island. He successfully sued the BBC and Lion TV for portraying him as violent. Returned to a presenting job on Channel 5, then moved to Sussex. He is now a psychotherapist.
Ben Fogle, 33
The most famous Castaway, his TV career has flourished with presenting jobs including Animal Park, Countryfile One Man and His Dog and Crufts. Lives with his wife, Marina, 26, a party organiser, in Notting Hill, west London.
Peter Jowers, 59, and wife Sheila, 58
Travelled abroad, then returned to their home in the Forest of Dean, which they share with three other couples, though they reject the term 'commune'. Peter teaches politics and philosophy at the University of the West of England, Sheila runs classes in painting and pottery .
Philiy Page, 31
The Castaway milkmaid moved to London and resumed her career as a photojournalist for publications including the Guardian, Marie Claire and the Radio Times. Retrained as a teacher but 'decided it was the worst thing in the world'.