It was in August when showrunner Shonda Rhimes stated in an interview with TVGuide.com, on her medical drama Private Practice, that she would love to "lure back Broadway star Audra McDonald (Naomi) one more time before the series ends."
Skip ahead 3 months later, to last November, to news that Audra McDonald would indeed return for the series finale of the show, which is set to air at the end of January.
McDonald would naturally reprise her role as Dr. Naomi Bennett, a role she departed at the end of season 4, so she could be closer to her New York-based family; she then went on to star in Broadway's revival of Porgy & Bess, for which she won a Tony Award.
As for what exactly her character's return to Private Practice would involve and could mean for the series, Rhimes promised "a death, some babies... and there could possibly be a wedding," suggesting that there would be a chance that Dr Naomi Bennett would be returning for 1, 2 or all of 3 those things.
Earlier today, the below video preview of that episode (titled In Which We Say Goodbye) surfaced, which I'd say answers the million dollar question (the series finale airs tomorrow, Tuesday, January 21, at 10pm on ABC):