Virtual Systems Analysis - S3-E16
Continuity mistake: When Annie is talking to Abed in the study room, next to Troy and Britta, the Dean's "Puttin' On The Ritz" cane is leaning against some books, towards the right. When the Dean comes back in to claim it, it is leaning towards the left.
Answer: The implication is that Jeff will still be teaching at Greendale after Annie and Abed leave. As for who became vice dean? It's never shown, since it's not really important to the series.
TedStixon