Final air date is not for a while - Sept. 25, 2011, according to CNN. She'll talk more about it during a live show tomorrow.

Here's more from the NYT:

After her broadcast talk show winds down, Ms. Winfrey will concentrate exclusively on her coming cable channel, OWN: The Oprah Winfrey Network. The channel is a joint venture between her production company and Discovery Communications. Getting the channel off the ground has proved challenging amid management turnover and an uncertain advertising climate. OWN will have its premiere on cable in January 2011, according to a person with knowledge of Ms. Winfrey's decision who insisted on anonymity. That timeline will theoretically give Ms. Winfrey about nine months to promote her cable channel on her existing show.