Hoover was Deputy Director of BATFE from 2009 until 2011 when he was reassigned due to the fallout from Operation Fast and Furious. He had been appointed the Special Agent in Charge of the Washington (DC) Field Division by Acting Director B. Todd Jones last October but was relieved of his duties in January 2012 along with Mark Chait and William McMahon. At the time, it was speculated that Hoover was relieved of his duties in advance of the Inspector General's report. That report still has not been either completed or released by the OIG.
Hoover had received bi-weekly briefings on Operation Fast and Furious but never shut it down despite reported misgivings.
This may be snarky but I'm sure Mr. Hoover is leaving with most of his pension intact.
UPDATE: Dave Workman, writing in the Seattle Gun Rights Examiner, has more on Hoover's leaving. Writing about this on Tuesday, Dave said:
William Hoover, former ATF deputy director, retired this week according to reliable sources. Hoover was the official who ordered an “exit strategy” for the operation when he realized its scope, but according to the report, that strategy was never followed. “Hoover,” the report says, “was also instrumental in briefing Department of Justice personnel about the status of Fast and Furious, and had previously discussed gunwalking concerns in another case with Bill Newell.”