I was doing a little digging around on Google for information on John Adams' On the Transmigration of Souls and found a good article on the piece from andante.com as well as an interview at the New York Philharmonic's site. Sounds like a pretty interesting piece (reminds me of Reich's Different Trains in the sense that there's a lot of recorded bits being used). I wonder if the piece, along with Guide to Strange Places, will be released on disc someday soon.
Update: There's also a review of the performance at the NY Times.