The IRS has recently updated their website with information on PTIN renewals.
The following item was posted to IRS.gov :
Q: What is the status of renewing Preparer Tax Identification Numbers (PTIN) for 2014?
A: Due to the lapse in government funding, the 2014 PTIN renewal season is delayed. An email or letter will be sent to all current PTIN holders notifying you when the 2014 renewal season opens. The online PTIN system is still available for users to log in and view or change information or to secure a PTIN for 2013. Additional information will be provided on this site as it becomes available.
Other Q&As related to the effect of the government shutdown on IRS operations are located here.