According to the press release, Nicole Beharie will debut as Imani Morehouse on the October 16th episode of CBS The Good Wife. The new season premieres Sunday, September 25th at 9pm et. Here's more info on the episode:

ALICIA TAKES ON A PRO BONO CASE WHERE THE WITNESS BECOMES THE ACCUSED, ON “THE GOOD WIFE,” SUNDAY, OCT. 16
Lisa Edelstein (“House”) and Harvey Fierstein (“Hairspray”) Guest Star
“Feeding The Rat” – Alicia takes on a pro bono case where the witness quickly becomes the prime suspect, but it’s Lockhart & Gardner that may be in the most jeopardy, as Will and Diane consider their futures and the firm’s direction, on “THE GOOD WIFE,” Sunday, Oct. 16 (9:00-10:00 PM, ET/PT) on the CBS Television Network. Lisa Edelstein (“House”) returns as Celeste Serrano, Will’s ex, and Harvey Fierstein (“Hairspray”) guest stars as Judge Francis Flamm.

She is listed under "recurring cast." So.. I guess it's more than a guest role, well, hopefully. :)

Of course, I will provide more info as it becomes available.