I am a minor coauthor on a paper to appear in Science. Sadly thats all I can tell you, since the embargo on this paper has been set for 2:00 pm U.S. Eastern Time on Thursday, 30 March 2006. Well, until next week :-)
OTOH, if you’re a reporter (hello John!) Reporters should contact AAAS at 202-326-6440 or scipak@aaas.org to receive an official version of the paper, bearing the imprimatur of the Science embargo policy. (Most reporters are registered with us and therefore can access the official version of the paper directly from EurekAlert!’s password-protected section, http://www.eurekalert.org)