The Center for Effective Government (formerly OMB Watch) ceased operations as of March 2016. The majority of work and materials has been passed on to the Project On Government Oversight (POGO). This site is being maintained as an archive of materials produced.
The FEC voted on the final rule for the 501(c)(3) electioneering communications exemption. There is no exemption for 501(c)(3)s.
Check out the final rule.