I feel like the problem with any specific spoiler rules beyond those normally in place is how exactly would people know about them? It would be unfair to punish people for a rule that they're unaware of.
That being said, if I see a thread title mentioning a specific game, I'll edit it out.
Another option is to make a stickied spoiler topic specifically for leaks relating to the Sony conference, so that people will have one topic, with a spoiler free title to post anything. I'll run that by the mods and see what they think.