Between this and the co-founders spreadsheet and the recurring 'Who's hiring?' threads, I think it's about time for a HackerJobs.com or something.
pg has built a singular and impressive user base, one which benefits from talking to and meeting each other.
I do agree a traditional jobs board would a lame add-on which would exist orthogonally to the stories/comments. Very soon it would be filled by stale jobs (startups move fast), recruiters and people who come just for the jobs section.
The current method of putting up a job post when it seems to be of most utility works, but just barely.
I just don't know if there's any feature you can add which would not feel like a cheap add-on but rather work within the current user-centric community.
I think the more personal "is anyone looking" is a much better idea.
Leverage whatever's keeping HN relatively spam-free.
Free to post listings, as long as the there is information about the company that is hiring. People can browse companies and listings by tags. Just put a "ycombinator" or "startup" tag there, and I'll approve it quickly.
Users that would like to get more details before applying can do so by registering and letting a comment on the listing page.