Go read. I have nothing else to say other than: Bravo!!
I have a few minutes so I would like to highlight this paragraph written by editor in chief Dr. John Maunsell:
Another troubling problem associated with supplemental material is that it encourages excessive demands from reviewers. Increasingly, reviewers insist that authors add further analyses or experiments “in the supplemental material.” These additions are invariably subordinate or tangential, but they represent real work for authors and they delay publication. Such requests can be an unjustified burden on authors. In principle, editors can overrule these requests, but this represents additional work for the editors, who may fail to adequately referee this aspect of the review.
In my opinion this is absolutely correct and gets right to the heart of what I think is wrong with science today. Our papers are ultimately about ideas and the experiments that either support or reject those ideas. The constant you just need one more piece of supporting evidence for everything mindset of many reviewers (I include myself in falling into this trap) is not useful to the process. The ideas in a given paper may or may not stand the test of time and that one more piece of supporting evidence is unlikely to have any influence on what that test of time will determine. The point is to get potentially influential ideas out there and to get them out earlier rather than later. Post publication experimental scrutiny is and will always be how the test of time determines the validity of new scientific concepts.