The answer at the delightful Passport office in Stamford (actually, they were really nice!) was that it's presently running "about four weeks from receipt...but we have to say it can take up to six weeks."

For what that's worth, of course; this answer was issued yesterday around 2pm. The Stamhattan folks were nice and efficient and all that other good stuff. Now if they can only make my poor passport photos look better...