[Update below]

Cathie Black, fresh off her dismal 17 percent popularity numbers, is reportedly stepping down as Schools Chancellor. Mayor Bloomberg is going to be giving a press conference announcing the change at 11:30 a.m.. For the time being she will be replaced by Deputy Mayor Dennis Walcott, NY1 is reporting. To quote Maggie Haberman's Twitter: "Cathie Black is Bloomberg's Harriet Miers."

The news that the former Hearst executive who came to the top education job in the city with no education experience will be vacating after just four months is a nasty setback for Mayor Bloomberg, who has made education reform a priority for his third and final term in office. But considering her her gaffe-filled first few weeks, the insanity of her appointment's waiver process and her dreadful approval numbers it isn't necessarily surprising. It is not entirely clear if she is going voluntarily or is being pushed out (the Times says her departure is "at the mayor’s urging" while the News' source says it is a "mutual agreement"), but the news comes hot on the heals of reports that the fourth major deputy in the department was leaving in as many months.

Black's replacement Walcott is set to appear with Bloomberg at the press conference coming up. The Times is reporting that Black herself will not be in attendance.

Update: Bloomberg, who has "nothing but admiration" for Cathie Black says the decision came because the story was increasingly about Black and not about the kids. But still he takes "full responsibility for the fact that this has not worked out the way we hoped or expected."

In the meantime Walcott—who started his career teaching kindergarten and has a masters in education but will still need a waiver for the job—appears to be the anti-Black. "I'm just a guy from Queens" he said today before pointing out that his family has had four generations pass through New York public schools (his parents, himself, his kids and now his grandchild).

While he transitions to the new job Walcott will continue to oversee the Department of Education as Deputy Mayor, though essentially he'll start on the new job immediately. His salary, when he takes the job, will remain at the Deputy Mayor level, which is lower than the Chancellor traditionally makes. In addition the Bloomberg will not be replacing Walcott with a new Deputy, allowing the city to save a few bucks.