I suspect the best course of action is to build it so that folks can better evaluate how compelling it is. I also doubt a Vbulletin-based solution is going to fly with this audience.
The way I see it the guy asked a question hoping to help the community and you are flippantly telling him his question is worthless; that you won't give him "actionable feedback" until he spends 20-30 hours on it. Pshaw.
Also, a side note was I'm also looking for developers/designers who would like to have this as a fun side (paid) job.
Webmasterworld uses a traditional forum software like vbulletin and it works quite well. Audience of HN and webmasterworld are not very different by standards.
I'm looking for others who are interested to take part in this new community board.