There has been quite a bit of discussion here, on the possibility of this being a completely new type of life (no common ancestor with other life). That would have been mind-boggling amazing indeed - but from what I read, it sounded much more likely that what they found where an more or less ordinary microbe that have substituted phosphorous the chemically similar arsenic (and still have the same nucleic acids, base-pairing, ribosome, protein synthesis etc).

Looking at the press release from Nasa, this is indeed the case:
http://www.nasa.gov/topics/universe/features/astrobiology_toxic_chemical.html

The newly discovered microbe, strain GFAJ-1, is a member of a common group of bacteria, the Gammaproteobacteria. In the laboratory, the researchers successfully grew microbes from the lake on a diet that was very lean on phosphorus, but included generous helpings of arsenic. When researchers removed the phosphorus and replaced it with arsenic the microbes continued to grow. Subsequent analyses indicated that the arsenic was being used to produce the building blocks of new GFAJ-1 cells.

It's still amazingly cool, but life as we know it is not falling apart =)

After reading through the comments on this story, it appears to me that there is significant confusion over what exactly Open Access means and how the peer-review process is handled. I have published quite a few paper in Open Access journales (BMC Genomics, Genome Biology, Nucleic Acids Research to name a few), and this is how it works:

*) One of the key differences between publishing in a traditional journal vs. an Open Access journal is that the final publication is freely available for all in PDF format from the publishers website following publication. The peer-review process is exactly the same as with traditional journal - as somebody else have already mentioned in this thread. Peer-reviewing is NOT something you are paid to do - is is solely based on volunteers (who are expects within the relevant field of research).

*) With Open Access journals you pay to have the publication "printed" (only if it get accepted through the peer-review process). This fee covers the expenses of editing and administration that traditional journal covers through their subscription fees.

*) Almost everybody searches for research papers on-line these days - either through Google or searching a specialized database like MedLine/PubMed. For Open Access journals the scientific publication will be directly available for download in PDF format - for traditional journals a PDF file will also most likely be generated - but it will only be available to subscribers (usually the University Library).

I hope this clears up a few things.

-Rasmus