Hi,
I think Roberto's suggestion is better. Or maybe page that lists the status of the contrib packages. On my case on particular snap shots it can go to contrib or work-in-progress. Goes back and forth.
And to be honest, in may case. There is a case of does-not-work-will-upgrade-later. I think either a single status page which list the current of all contrib packages. Or a status page on each package as Roberto suggests. From what I recall before I started to put my packages there, it was no criteria. The sole criteria was, you wanted to share your code. Or I guess that is what I have been told and understood.
Because putting it on a dir to give status seems to bring the barrier up again. And we may end up will a lot of dirs, like contrib, work-in-progess, work-halted, etc. Maybe a contrib/STATUS page can be used. Since I think most contrib people will have access to that page. We just update it from time to time when ever we commit new code.