The story is being made into a movie. Here is a trailer.
Wagner has an opera on the same. According to this link (again)
Tristan and Isolde is considered one of the most emotionally gripping operas ever written, and is, perhaps, Richard Wagner's greatest work.
To listen to it.
update(12/21): Shyamala Narayan's Raja Rao: Man ans his works has the story of Tristan and Iseult. Also, it has a comparision of The Serpent and the Rope with The Waste Land by T.S.Eliot.
A much later update(01/14): According to the review in NYTimes and also other places, it seems the movie was not well made.