The IRS just announced that if you've had a 501(c)(4) application languishing for more than 120 days, then they will allow you to be able to "self-certify" (subject to audit down the road of course) that you are in fact a proper social welfare organization.
Essentially, you have to declare under penalty of perjury that political campaign intervention involves less than 40 percent of both your group's financial expenditures and your group's employee/volunteer time. These thresholds apply for past, current and future years of operation. Those groups that decline to utilize this expedited review procedure are told that they will not be punished or treated unfairly and will be evaluated under the applicable facts and circumsances test.
The unique question, though, is what should organizations do that might have campaign intervention that exceed the 40 percent level, but are still below 50 percent. Under the normal rules, up to 49 percent of campaign interventions are ok, but you would be unable to self-certify under this new procedure. The most difficult question is what happens to those organizations who self-certify, and then, unexpectedly, intervene politically at some level just above 40%. Normally, this wouldn't be an issue, but it is unclear how this would be impacted by the fact that you certified to something otherwise. By self-certifying you may be giving up on your groups full ability to engage in allowable political campaign intervention.
A sample of the new form that will enable certain 501(c)(4)s to self certify is here (by invitation only from the IRS though).