"New" rules (really just part of the first, and which have always been in place, but now nobody can bitch about not having it explicitly said...)
2. Type properly. You know how you type essays and such? It shouldn't look as horrid as your average Internet speech, because that's the first step to more intelligent discussion.
3. Have respect for the things people do. No begging, no nagging, etc. And keep feedback constructive.
4. Have respect for people, too. You know. Keep it friendly.