Here is an interesting discussion on the academia stack exchange:
Does any publication venue make rejected papers available for download?
This leads to an amusing paradoxical question for ERROR workshop:
Could it be called a success if a paper gets rejected from a workshop on negative results?
A more interesting and intriguing question though is, should conferences strive to make the rejected papers and reviews available? Certainly issues such as author permission, anonymity etc. will be needed to address. A key point is whether this will help hasten the progress and make the community aware of what were the flaws in a given piece of work? Would such a practice make workshops like ERROR redundant and unnecessary?
All interesting questions to ponder, I think.