If a Paper is Submitted to Nature, Does it Still Make a Sound?

Suppose you (and perhaps a competing team) had an incredibly exciting discovery that you wrote up and submitted to Nature. Now suppose that you (and the competing team) simultaneously posted your (competing) papers to the ArXiv preprint server (which essentially all astronomers and physicists visit daily). But, suppose you then wrote in the comments "Submitted to Nature. Under press embargo". In other words, you wrote the equivalent of "Well, we've submitted this to Nature, but they won't might not accept it or publish it if the news gets into the press, so can all of you reading this just not actually, you know, tell anyone? Oh, but can you make sure that you give us credit for the discovery, instead of the competing team? Thx!" So, instead of blogging about the Incredibly Exciting Discovery (which I'd loooove to talk about), I'm writing about what a ridiculous fiction the authors are asking us all to participate in, for the sake of the authors' potentially getting a publication accepted to Nature. The authors advertised a paper to thousands of interesting, engaged scientists, who are then supposed to keep their mouths shut so that the authors can get a paper into a particular journal -- one that is not noticeably more influential in astrophysics (i.e. the difference between Nature and non-Nature is not nearly as big a deal as it is in biology). Look folks, either come up with an agreement with the competing team to both shut your yaps until both your papers are simultaneously released from embargo, or suck it up and just submit the paper to the Astrophysical Journal or some other high prestige journal that doesn't require Nature's crazy embargo rules. Your result is terrific, you should be rightly proud, and Nature should be honored to publish your work. But, if a publication in Nature is really the goal you're after, asking all the rest of us to be complicit is a bit silly. Plus, I'm wiling to bet that Dennis Overbye skims astro-ph... Update: Lots of good discussion and insight in the comments, so worth clicking through.