Ah, but will people show discretion in a spoiler thread? By it's title, does that not imply they can post whatever and not bother with spoiler tags?
First, to be clear, I think the Zelda thread went fine. I'm just curious how a separate thread will work out.
I was envisioning a spoiler thread as more of knowing it as a place where there will be spoiler-y talk, not necessarily that it will be unmarked. If you look at the Zelda thread, it has lots of posts, and someone beating the game later could have trouble going back and reading some of the thoughts about, say, the ending, and having trouble starting a conversation about it. Maybe a spoiler thread will make it easier for people to have discussions about later-game stuff without sifting through posts.
Whether people mark spoilers or not, I'm at least envisioning people prefacing their posts with the section they're going to talk about, so people know what they're getting into by reading it and know if they've played that part. Is that clunky? Maybe, I'm not sure. I know there are still some problems with the idea and we don't have to do it with every game, but we'll see how it works out and it may not be a bad idea to do with larger games like this. After all, I feel like some games are too large for just one thread, so it's more about sorting categories for a game.