Ed Lee has taken his time, but now sources tell the Chronicle that the mayor has chosen his choice. Neighborhood activist and businesswoman Julie Christensen will be appointed District 3 Supervisor. She'll be filling the seat vacated when former board president David Chiu was sworn in to the state Assembly in December.

Christensen is a Telegraph Hill resident and a member of the advisory board for the urban think tank SPUR. She was a strong advocate of the new North Beach library and pushed for the renovation of the Joe DiMaggio playground. She's also written that she'd like to see the Central Subway extend to North Beach and Fisherman's Wharf. Christensen knows business, is thought of as relatively moderate on development, and founded the product design consultancy Surface Work.

According to Lee's schedule, at 1:00 PM today the mayor will announce the appointment, though it doesn't say of whom. The Board of Supervisors is scheduled to convene its first meeting of the year tomorrow, and presumably Christensen will be sworn in at that time. She could, explains the Chronicle, cast an important vote for the next board president and even serve ten years in office. That is, if she can fend off challengers who might perhaps be irked by her appointment, such as former board president Aaron Peskin.

C. W. Nevius recently called this shot, explaining that it was probably better to pick Christensen over another possible front-runner for the job, Cindy Wu, the president of the Planning Commission. Of Ed Lee, Rose Pak told Nevius, “I think he worries too much.” Well, Lee certainly seemed worried when Wu voted against the proposed 8 Washington development, which he's called his legacy project

Anyway, be sure to mention Christina Olague in the comments.

Update: In hindsight, the appointment should have been patently obvious at 11 this morning, when Ed Lee's office gave the media the location of the announcement. Speaking from the steps of the library Julie Christensen supported, Ed Lee announced her appointment.

Here's Ed Lee:

“I am very proud to appoint Julie Christensen as the new District Three Supervisor,” said Mayor Lee. “As a longtime District Three resident and small business owner, Julie has worked tirelessly on important projects and neighborhood concerns including the North Beach Library, the Central Subway and numerous pedestrian safety projects. I know Julie will be a strong advocate for tenants and for all of the families, youth, seniors and small businesses in the diverse neighborhoods that make up District Three just as Supervisor David Chiu was for so many years. Julie shares my vision of creating a stronger and more affordable San Francisco with a focus on inclusiveness, jobs, housing and world class transit.”

Previously: Mild Intrigue Surrounds Mayor's Possible Appointment To David Chiu's Board Seat, Board President Vote