The way I see it, I think people should avoid giving away spoilers for about three weeks after a movie is released. People can't keep their mouth shut about movies forever. However, there are some parts about the movie that I wouldn't spoil because they're just that epic. What I gave away is hardly anything worth not giving away, especially since we saw from the end of the second movie that the romantic hints were probably going to happen anyway. Not only that, they show it in the previews. So, I didn't reveal anything that wasn't already given away in the previews.
I think as long as people just don't give away an ending, people need to lighten up a bit about spoilers. I've been spoiled a lot, and it really doesn't bother me, because I know that sometimes it's unavoidable if you're on the interbutts a lot.