Check out the National Park Service Press Release regarding the disposition of Culturally Unidentifiable Individuals. This was a very hot topic for discussion at the recent SAA meetings!
Tons of information on this subject, including debates surrounding new additions to the law, can be found at the UC-Berkeley/NAGPRA Blog.
The National Park Service has a web site dedicated to Kennewick Man, which includes link to all the technical reports produced by archaeologists, physical anthropologists, etc.
Last thing... if you are interested in how Kennewick Man has been used and abused to promote a number of competing (and often scary) agendas, do a Google Search for both images and text.