The American Society for Cell Biology (ASCB) has issued an open access position paper ("ASCB Position on Public Access to Scientific Literature").
Here is an excerpt:
The ASCB believes strongly that barriers to scientific communication slow scientific progress. The more widely scientific results are disseminated, the more readily they can be understood, applied, and built upon. The sooner findings are shared, the faster they will lead to new scientific insights and breakthroughs. This conviction has motivated the ASCB to provide free access to all of the research articles in Molecular Biology of the Cell two months after publication, which it has done since 2001. . . .
Some publishers argue that providing free access to their journal’s content will catastrophically erode their revenue base. The experience of many successful research journals demonstrates otherwise; these journals make their online content freely available after a short embargo period that protects subscription revenue. For example, as noted above, the content of Molecular Biology of the Cell is free to all after only two months, yet the journal remains not only financially sound, but profitable. The data clearly show that free access and profitability are not mutually exclusive.
Our goal should be to make research articles freely available as soon as feasible so that science and the public benefit from their expanded use and application. At the same time, it is important that nonprofit societies and other publishers generate sufficient revenues to sustain the costs of reviewing and publishing articles. We believe that a six-month embargo period represents a reasonable compromise between the financial requirements of supporting a journal and the need for access to current research.