The widespread adoption of the open access arXiv.org preprint server has forced the hands of twelve journals in particle physics that account for about 90% of published particle physics papers. They are on the verge of dropping their pay walls. The deal would be fully in place by the end of 2014. The journals will receive $650 to $2,000 per paper in exchange for releasing their content to the general public, rather than merely journal subscribers. Journal subscription fees will also fall.
The reality is that almost nobody ever actually pays for access to a physics paper behind a pay wall (which costs as much as an entire used college physics textbook in good condition). The pay wall simply serves as a means of compelling professionals who regularly use the articles to have their institutions pay the hefty journal subscription fees.
The lives of the institutionally affiliated journal subscribers will change little under the deal, which also had little net financial impact on their institutions. But, the deal will tremendously increase access to these articles in their final published form for the educated lay public and physicists in industry, working in high schools, or working at small institutions who can't afford journal subscriptions, for example.
Wider distribution benefits the scientists publishing the articles, whose ideas are more widely distributed as a result. For example, nobody wants a Congressional staffer or lobbyist considering science funding to overlook their latest paper because the staffer or lobbyist doesn't have a journal subscription and doesn't have time to get a copy from someone who does. This is part of the reason that arXiv.org received such a warm reception and wide adoption by the people whose ideas were supposedly being managed in a revenue maximizing way by the journals.
The lag between pre-print publication and journal publication has also reduced the bargaining power of journals for established authors whose ultimate publication is almost certain, because the official version is almost always scooped and an active science blog and science journalism and professional physicist community monitors new pre-print releases very actively.
The journals themselves are mostly organized as non-profit organizations, really de facto producer cooperatives, that essentially just need a way to finance the process of organizing the administrative and printing work that goes into sorting the wheat from the chaff of new publications and organizing the work of quality scientists into presentable form. The printing part of that process has almost vanished. These days, the publications are written in electronic formats, edited electronically, and mostly read in electronic formats as well by journal subscribers. Every year more academic journals drop their print versions entirely, or print just a handful of copies as collectors editions that are more for show than for practical use. The thinning of the amount of work done by the journals themselves in house with the decline of printing as also reduced their clout. For the most part, their in house staffs could easily be replaced if the institutions who subscribe to their journals mutually agreed that they were being gouged and started a new publication over which they had more control instead.
Unlike music, television, movie and authors who write books that are sold in bookstores, scientists do not receive substantial royalty income from the publication of articles, even though they do receive considerable financial benefit from publishing articles. Indeed, the time that published scientists contribute to the peer review process as volunteers pretty much outweighs any services they receive from journals in connection with the articles that they publish themselves. Some of this flows from the fact that basic scientific laws and principles can't be protected by patent law anyway, and that copyright protects particular ways of expressing an idea rather than the idea itself.
Instead, scientists benefit from having published articles by using that signal in the hiring and promotion process within the world of professional scientists in and out of academia, in attracting top talent to join their labs as graduate students and post-docs, in selling higher level science textbooks that do bring in meaningful royalties, and by bringing their work to the attention of people who award grants and prizes for work in their field.