ArXiv submission?

I'd like to put our arseniclife submission to Science onto the arXiv server so that anyone who's interested can read it.  Not many biologists use arXiv (it's mainly a physics thing) but it's a very convenient place to post manuscripts and other documents.  And its use by physicists provides a great precedent for open science, because manuscripts are posted there and submitted for formal publication in peer-reviewed journals.

 Distribution on the Internet may be considered prior publication and may compromise the originality of the paper as a submission to Science. Please contact the editors with questions regarding allowable postings.

Has anyone had direct experience with this?  I think I'd better send out a tweet...