From AF Times regarding Wynn's successor:
Gates is likely to recommend Michael B. Donley, the Pentagon’s director of administration and management to succeed Wynne, a senior defense official said Friday.

Donley was acting secretary of the Air Force for seven months in 1993 and served as the service’s top financial officer from 1989 to 1993.

Air Force Vice Chief of Staff Gen. Duncan McNabb will likely become acting chief of staff.
Full article here.