Diggs was seen recently on ABC in the short-lived television series "Day Break." His casting in the new show is a result of an ABC-TV studio deal he signed as a talent for his production company O'Taye Prods.

Walsh appears on the popular medical drama "Grey's Anatomy" as neonatal surgeon Addison Shepherd. The possible spinoff — to hit the small screen as early as May as a "back-door pilot," an expanded two-hour episode of "Grey's Anatomy" — will center on her character "on the verge of leaving Seattle Grace," the hospital where she currently serves.

"Grey's Anatomy" creator-executive producer Shonda Rhimes will pen the episode and is expected to shepherd the potential series, the trade mag reports.

Diggs last appeared Off-Broadway in A Soldier's Play. He lent his dulcet tones to the hit movie musical "Chicago," the film "Rent" and TV's "Will & Grace." The actor seen onstage in Carousel, The Wild Party and Chicago is perhaps best known for originating the role of Benjamin Coffin III in the musical Rent — where he met his wife Idina Menzel. Diggs has appeared in the films "How Stella Got Her Groove Back," "Go" and "The Best Man" as well as on television in "Ally McBeal," "Ed" and the title role in "Kevin Hill."

Walsh is also a veteran of the stage. The San Jose, CA, native became involved in regional theatre while attending University of Arizona. She then headed to Chicago and worked with the Piven Theatre Workshop and the Chicago Shakespeare Repertory, appearing in Born Guilty, Moon Under Miami and Troilus and Cressida. In New York City she performed onstage with the comedy troupe "Burn Manhattan" and in the Off-Broadway plays Flight Courier and The Four Twins.