At the tail end of last year we were all excited by a discovery by a group of NASA supported researchers who announced a major finding stating that the 'Definition of Life had Expanded'. That was based on their apparent discovery of a tiny life form that replaced Phosphorous (P) for Arsenic (As) in its DNA. Phosphorous has long been on the list of chemical elements needed for biological life, and there has been much history of debate surrounding the idea that As could possibly be used as a replacement for P, due to similar chemical structures. However, As was largely dismissed probably because it forms a weak bond compared to P, and of course, because no life had been found to ever use it. If the research turns out as being proven, it would still only account for a replacement of a small portion of P for As. This research, to the best of my knowledge, was a project put forth by NASA with the research goal being "Can Arsenic be used to replace Phosphorous by an Organism?" - or something close to that effect. Thus, through their work, they found what they were looking for. The question becomes, did they find it concretely, in a reproducible manner, that can withstand peer-review?
Days after the mass media hysteria, and the litte-green-men-theorists celebration, a very well written blog article was published that questioned multiple aspects of the findings. The primary criticism was that there were many possible explanations for the growth of the bacteria within the arsenate solution tested, among many other issues. Shortly after that, the lead scientist on the team who published the initial finding published a response to the criticism. 
In sum, they cleared up some misconception, but still left much room for debate and alternative theory, and did not provide a proof-positive concrete rebuttal. The paper also stated ".. their evidence suggested arsenic had replaced a small percentage of the phosphorus in their DNA." It ended on the note that they welcomed further review and experimentation by the scientific community. Days later, another blog article rips the response to even finer shreds. This must be the French Quarter, because this party never ends! So, until we have additional studies done, with more stringent controls, we still do not have proof that a truly alternative life form has been found on Earth (or extra-terrestrially). Thus, the Definition of Life is apparently Receding - back to what it was, for now. Did they find what they were looking for by giving in to what they wanted to see, rather than what the results really shewed? The detailed criticism makes that notion seem quite plausible and probable.
What bothers me most about this whole debacle is the way in which the information was presented. It was kept under wraps by way of an embargo, even from the media and other scientific organizations until the last minute. The announcement was a whopping, highly anticipated, highly publicized, pending announcement, dubiously entitled "astrobiological finding that will impact the search for evidence of extraterrestrial life". Who wouldn't be interested to know what they were talking about. We found ET? That title surely alludes to the idea. You can only deduce two possibilities from a title like that; Either "The impact on the search for ET is that the search is over because we found ET", or "What they found will impact the way we search for exo-life". Sure, the less crazy of us figured it was the latter. However, what kind of half-baked, super-hype is this? Every ET fanatic on the planet started buzzing with wild fanfare. Twitter, Facebook, news feeds and blogs alike went nuts with ET fever. Everyone and their brothers (and sisters) showed up for the announcement event of the century! Only to be slightly amused at the expanding definition of life, by the discovery of a local microorganism that uses arsenic instead of phosphorous. Sure, we can celebrate around the idea that what we thought of as life was narrow, and we can look to other planetary systems with arsenic as possibly containing forms of life. Sure, we could conclude that there may be even other chemicals that would still further expand on what we know of as life. Mild, very mild, amusement. They should have been a bit more clear from the get-go as to what they were going to present.
Take note that NASA was less than a month away from a major budget cut. Naturally, the first thing that comes to mind is "What can we do to save the budget? Ah, yes, let's give them ET - or least a plausible ET." Okay, it might be doubtful that it was their intention to try and stave the budget crisis through this announcement, and sounds like a raving conspiracy theorist rant. However, leaving the public squirming around with the notion that we had discovered little-green men for such a long time sure makes the conspiracy theory argument compelling. Nonetheless, it's nothing we can prove, and it would arbitrary at best. The easily misinterpreted announcement was very badly titled, badly organized, badly timed, and scientifically unsound. They should have simply published their findings, like any other scientific discovery, and let the scientific process work as it should. Looking back, at what is now a highly debatable finding, makes this even more apparent. You can not do scientific research in a bubble, without corroborative reproducible results. That can only be achieved when you release your findings to the rest of the scientific community as a hypothesis, not as a finding for mass public promotion. It's just very bad science. What would have been interesting research, has become a joke and a slap in the face of real science.
Don't get me wrong, I would love to hear about a simple organism found elsewhere in the universe, or "intelligent" life elsewhere. However, this shoddy example of a supposed ET, even if proven true, still does not come close to an expansion of the definition of life. It's more like a pushed example of a possible and minor adaptation. Swapping out a couple P for As here and there, even if true, doesn't mean we'll find pure As built microbes somewhere, it's just too weak. P, so far, must still be the primary building block. I wish that an ET discovery would come true, though I doubt it will happen in our lifetime. I'll keep the margaritas on ice, just in case.
Update 5/5/2012: Could this be the end of it? Rosie Redfield, et al., have published their peer-reviewed research: Absence of arsenate in DNA from arsenate-grown GFAJ-1 cells
You can follow @RosieRedfield and #arseniclife
Links & References For your reading pleasure, if so interested:
NASA Announces ET Impact - Embargoed
The NASA Discovery Arsenic-Bug Findings
The Criticism of the Arsenic-Bug Research, by Rosie Redfield
The Criticism Expanded Upon, by Carl Zimmer
The Response to the Criticism, by Felisa Wolfe-Simon
The Criticism of the Response to the Criticism, by Rosie Redfield
A Backup Copy of the Response (Just in case they remove the doc)