To sum up: Guest posting is allowed. It has been like that for a long long time and unless something drastic happens it's likely to stay that way. Guests need to solve a captcha on every post in order to prevent spam.
Should anyone feel the need to discuss the current arrangement please open a new thread in the feedback section. I'm closing this thread since it's really an announcement about a temporary situation a year ago.
Code of conduct, suggestions, and information on forums.debian.net.