Update 8/5/2008: NASA has issued a press release which indicates the potential discovery of perchlorate on Mars, a chemical which may make Mars less habitable than previously thought. You can follow the Mars Phoenix team’s twitter log here.
Aviation Week is reporting that the Bush Administration’s Presidential Science Advisor’s office has been advised of information that NASA plans to release sometime between mid-August and September 2008 concerning the habitability of the Phoenix landing site and the potential for life on Mars. While not directly pointing to evidence of life currently or in the past on Mars, the information is apparently "far more provocative" than previous announcements confirming the presence of water.
This information will be of concern to Oxford professor Nick Bostrom, because of his recent argument regarding the Fermi paradox and the implications that the discovery of extraterrestrial life would have for the human species.