I happened upon the current issue (Spring 2007, volume 60, no. 3) of the scholarly journal
Film Quarterly in the periodicals section of my library today, and discovered that a substantial portion of the magazine is devoted to the film
Brokeback Mountain. Eight articles, including an introduction to the pertinent section by Rob White, critically engage the film and its social and cultural ramifications. It is unusual for the editorial board of
Film Quarterly to essentially dedicate an issue to one film, but White argues that
Brokeback Mountain's significant and continuing sociopolitical impact merits the most serious scholarly attention.
I was not able to do more than scan quickly through the issue, but I found the website for
Film Quarterly that reproduces the cover, provides the table of contents, and allows for a PDF download of White's introduction and a plot synopsis of the film (there are some questionable assertions in the latter that suggest, at the least, a minimal exposure to Proulx's original story). Here is the direct link to the site:
http://www.filmquarterly.org/index2.html