Pope's Word is absolute law.
Oddly enough, the Episcopal Church is more liberal than the tree it's a branch of (Anglican Church) because in the Episcopal Church, we've had women priests for... how long? In the Anglican Church, that's still an issue of sore contention for some reason.
You know altar boys? The kids that help out around the altar? Vatican II allowed for both female and male altar kids. Catholic Churches (I would say community, but to ROman Catholics, the Church=It's Community. The building is highly unimportant to worship.), as a whole, have been excommunicated for not allowing female altar kids. It still took a whopping 50 years (2010) to finally decide that they'd prefer not to be excommunicated and allow female altar kids. Just to show you how resistant some folks are to change.
Pope, by the way, isn't the Catholic Emperor or something. He can make, very occasionally, with very strict rules and definitions, make a statement that is inerrant. I can't remember the exact rules (Except it requires him to sit in a specific chair), but not everything the pope says is law or even without falsehood. But if the Pope decided something without a council, it generally is not law by tradition. Sorta... the evolution thing is that way. The Pope, John Paul II, believed in evolution and established guidelines for Catholic belief on it, but it wasn't part of Vatican II (That was the last major council that really shook things up in the church) and it's not heresy/excommunicable to not believe in Evolution for a Catholic. Why a Catholic would not is really annoying thought, though.
Honestly, if the Catholic Church allowed women priests, allowed homosexuals to marry, and allowed contraception I'd probably still be part of it (Lack of reason to dig and bring up other contentions). Though they do tend to have a much better stance on most homosexuals than most hardliners. No marriage, but they understand it's not a choice and there's no sin in being attracted to the same sex. There's no sin in the attraction, just the action. It's not wodnerful, but it does show they are grappling with the subject better than fundies.