Maybe he's a chameleon... he didn't advocate or see how women could be priests when he wrote "Priests in the United States" in 1971 and he doesn't now in 2003 from what I read.
Some quotes:
Father Greeley, a balding, 72-year old who wears a priest's trademark black, Roman collar, has often found himself at loggerheads with the Catholic Church; on a broad range of matters -- from the Church's opposition to artificial birth control to its objection to women priests.
Another:
At the same time, Father Greeley favors -- as he puts it -- a "relaxation" of the celibacy rule in the Catholic Church to attract more seminarians.
"The truth is that, for most of the Church's history, it was a vow that wasn't really enforced. It probably is going to have to be relaxed -- maybe even in the next papacy. Because there are so many bishops in the world that think that and keep quiet about it, and because priests are needed. We need more priests."
Greeley favors celibacy, but's not really opposed to married or women priests.