Bye Bye? Could be booted out...
According to Wikipedia, Oefelein was commissioned an ensign in 1988. If he has any say in the matter, he'll stay in another year or so until he completes 20 years at which point he can retire on half-pay for life.
HOWEVER, his dalliances with Nowak and Shipman may constitute "conduct unbecoming an officer" under Article 133 of the Uniform Code of Military Justice. That being the case, they could conceivably court-martial him, dismiss him from the service and forfeit his pay (including his retired pay).
I suspect that, at worst, he'll be given nonjudicial punishment under Article 15 of the UCMJ and given a formal reprimand. At best, he'll get an informal letter of reprimand that will sit in his service records and effectively prevent any further promotion. The fact that Oefelein, a qualified fighter pilot, wasn't given an operational assignment (i.e., to a fighter squadron or at least to a carrier air wing staff) suggests to me (ex-Navy JAG) that he's being pressured out of the service. Not only is his career effectively over, but they'll give him crap jobs to "encourage" him to leave as soon as possible.