A more detailed critique. http://rrresearch.blogspot.com/2010/12/arsenic-associated-bacteria-nasas.html .
The Mars meteorite paper was also published in Science. Here is the paper abstract. The paper is not available for free from Science. http://www.sciencemag.org/content/273/5277/924 .
Perhaps the most widely known and notorious 'science by press conference' saga happened in 1989 with the cold fusion experiments. http://en.wikipedia.org/wiki/Cold_fusion .