From the NY Times:
Musical chairs in government is hardly a new phenomenon. But what makes Mr. Bloomberg’s situation noteworthy is that he has presided over a cabinet that has experienced remarkably little turnover and minimal controversy.
Now, though, the stakes are especially high, since Mr. Bloomberg is gearing up for a re-election campaign that is predicated chiefly on his record as an effective manager and a brand-name nonpolitician who has recruited top talent. So the question, according to political analysts, is whether the increased churn in personnel is merely a hiccup or a precursor to additional problems — the kinds of problems that have typically plagued third terms.
Some say that by the end of the year, Mr. Bloomberg may lose some of the original staff members who shared his passion and commitment, and are now just exhausted or looking for lucrative private-sector jobs. So he may not have as much success hiring unorthodox officials for a third term that he has said would be his last, and may instead resort to simply promoting from within.