Not a surprise after how he left: Terry Semel is leaving Yahoo’s (NSDQ: YHOO) board; this is his last day. “Semel initiated discussions with the Board several months ago about stepping down from the Chairman role once the Board was able to identify a successor. He targeted the time of the January Board meeting for his departure…Roy Bostock, who has been a member of the company’s Board since May 2003, was unanimously elected by the board to serve as Yahoo’s non-executive Chairman.”

Semel joined Yahoo in 2001 as chairman and CEO, relinquishing the CEO title during a June shake-up to co-founder Jerry Yang and becoming non-executive chairman of the board. We reported earlier this month that Semel is pumping up his own company, Windsor Media; most recently, reports have surfaced that he may be interested in acquiring a movie studio.

—Bostock is a former chairman and CEO of D’Arcy Masius Benton & Bowles and its successor, The MacManus Group. He’s also on the board of Morgan Stanley and is currently chairman of the board of Northwest Airlines Corp.

—Semel’s departure leaves Yahoo with 10 board members, nine of them independent. The tenth is Yang.

Here’s the release, which includes a list of Semel’s accomplishments and only the slightest allusion to the issues facing Yahoo in his wake. More here and more to come.