It looks like the Writers Guild of America West has some concerns about SOPA. In a recent post on the trade group’s site, they wrote about a recent visit to Washington D.C., where they met with various lawmakers and other trade groups about SOPA and other legislation they think is important such as Net Neutrality and the ATT/T-Mobile merger. From the paragraph about their visit to the House of Representatives (I’ve highlighted the important stuff for emphasis):
"On the House side, Keyser and Barrios met with Reps. Henry Waxman, Howard Berman, and Janice Hahn. They thanked Waxman for his strong support of Guild issues and discussed concerns with the recently introduced Stop Online Piracy Act (SOPA). Because Berman is a co-sponsor of SOPA, the pair discussed their concerns with the bill’s implications for competition and an open Internet. Although the WGAW strongly supports combating piracy, the competition, First Amendment, and due process concerns the bill creates must be addressed. Berman said he wanted to work with the WGAW to address the issues and asked for input on the legislation. The meeting with Hahn, newly elected to the House, was an introduction to the Guild’s public policy program and an opportunity to explain our work with the FCC and other members of congress."
They also addressed their concerns with Chris Dodd, chairman and CEO of the MPAA, Markham Erickson of the Open Internet Coalition, and Gigi Sohn from Public Knowledge.
You can read about their entire visit here. While it doesn't sound like they have abandoned SOPA completely it seems that they have serious misgivings about some of the same issues that internet rights' groups do.