I've been looking for a good way to gather information from my users/potential users about what features they could best use. Handmade Network is already the best place to find those people but the only mechanism of information exchange is the forums which does not allow the kind of information gathering I want.
The minimum feature set that I would want to make something like a "survey" would be:
The ability to make all responses to a thread private so that if a user posts there answers will only be known to the thread owner.
The ability to make a thread where each user can only post once (allowing for edits perhaps).
The ability to make responses anonymous even to the thread owner.
The ability to put a time interval on a thread so that it can only be posted to during that time.
The ability to download a "transcript" of a thread as a text file or something.
The reason I don't just use a "survey" service, is that I don't really want to ask questions by constructing a form, I want to offer a few prompts and have people respond back in written form. If this were to become a big part of the site, it would be nice to have a "current surveys" block on the home page or something that lets me know when I can go fill in questions to support other projects too.