Apparently if Bernanke is not reappointed, he can still lead the FOMC for a long-time. He would only lose the position of chairman of the board of governors but can still lead the fomc as the fomc chairman is decided inside the fed(usually they just vote for the chairman of the board of governors but there is no obligation for that)
http://blogs.wsj.com/economics/2010/01/22/does-bernanke-delay-affect-next-weeks-fed-meeting/
http://blogs.wsj.com/economics/2010/01/22/does-bernanke-delay-affect-next-weeks-fed-meeting/