The Chronicle of Higher Education has an interesting article on open access publishing. It notes what many open access advocates don't. Publishing, even online, requires resources, which costs money, which some has to provide.
One of the benefits of the traditional publishing model is that the customer, libraries, associations, and individual subscribers, paid. Consequently, journal editors had an incentive to provide a product that people were willing to buy.
In contrast many open access publishers charge a publication fee to the author. Unfortunately, this scheme does not create incentives to publish good papers. The publisher does not get compensated unless they publish the paper. While there are some legitimate open access publishers that charge a publication fee, many unethical entrepreneurs have stepped into the field to publish anything as long as they get paid. See Beall's list for some sense of how many there are. These publishers have an incentive to publish any crap as long as they get paid because they know that no one is going to read, let alone pay for, The International Journal of Business and Social Research or World Journal of Social Sciences.
I have had people try to defend the pay to publish model by saying that a lot of good journals charge fees. Those good journals charge submission fees. The incentives created by submission fees are exactly the opposite of those created by a publication fee. Submission fees encourage authors not to submit crap. Publication fees encourage journals to publish crap. They don't get paid if they don't publish the paper.
I'm not opposed to open access, and I certainly don't support Elsevier, but I don't like it when people champion open access without regard to the consequences.