The first day of the Television Critics Association summer press tour brought with it a TCA ritual: news that a network president had been asked to leave his post, in part so the replacement can answer every question at his press conference with, "Uh, I just got here."

As first reported on by Vulture's Josef Adalian, ABC entertainment chief Stephen McPherson has settled out of his contract with the network and left, effective immediately.

UPDATE: ABC issued an official statement about the resignation: 

Steve McPherson today submitted his resignation as President, ABC Entertainment Group, and the Company accepted.  Mr. McPherson said, "I want to thank the wonderful team of individuals who have worked with me throughout my time here and wish them nothing but the best.”  A replacement for Mr. McPherson will be announced shortly.

After years of running Disney's television studio under its various names, McPherson took over the network before the 2004-5 TV season. That year was a turning point for the network, thanks to three shows - "Desperate Housewives," "Lost" and "Grey's Anatomy" - that had been ordered to series by McPherson's fired predecessors Lloyd Braun and Susan Lyne, and developed in part under McPherson's guidance at the studio. (Braun had, in fact, largely come up with the idea for "Lost," though J.J. Abrams and Damon Lindelof greatly expanded on his concept of doing "Survivor" as a scripted drama.)

The network's fortunes under McPherson's leaderships largely rose and fell on the backs of those three dramas and "Dancing with the Stars," which debuted in the summer of 2005. Though ABC has developed some other modest hits in the years since ("Castle," "Private Practice"), last fall's launch of "Modern Family" was the network's first notable standalone success in several years.

Update #2: 

Variety is reporting

that McPherson will be replaced by ABC Family's Paul Lee.