When natal Moon is out-of-bounds (OOBs) of the earthly plane one tends toward unconscious motivations that can result in unusual fame and prominence and/or emotional roller coaster rides and instability.
Oprah Winfrey's Sagittarian OOBs Moon in 4th house, one of the psychological houses, emphasizes the tendency of an OOBs Moon toward extraordinary achievement but also indicates compulsive eating and obsessions with food and diet as stand-ins for defective mothering in her childhood. A need to tell the truth (Sag) is evident in almost every show she produces, undergirds her in her professional pursuits, and is also described by a 4th house Sag Moon that is OOBs.
Ms. Winfrey's last show on network TV has been announced for September 2011 when she begins broadcasting on her 'OWN' cable network. How many broadcasters can say that, female or otherwise? What a gal!
Yes, the astrological Moon has associations with the public and thus with fame, and an OOBs Moon can create an overachiever such as Oprah, one of our celebrities known and instantly recognized by only their first names, so you may wish to read more by the excellent Pamela Welch in her article Those Wild Out-of-Bounds Planets. For details on Oprah, read past the Linda Tripp info, a lady who publicly expressed more the negative side of an OOBs Moon.
Actually OOBs planets in general can indicate genius or unstable behavior so check out the article's Parts 1 and 2 for that; linked above is Part 3. It's the lunar involvement that brings in the substitution of fame, prominence, and material security to fill an unfillable gap caused by insufficient mothering in childhood.
Oprah Winfrey gave on-air her birth data as: Jan 29, 1954 @ 7:51 pm (+6:00) in Kosciusko, Mississippi; Ms. Welch's article states Winfrey has a 12th house Moon, but the data here gives a 4th house Moon conjunct asteroid Siva (creator/destroyer goddess) and Sigma (significance, upright morals), all three in the 11-13 degrees of Sagittarius and conjunct natal Ic.