Love this idea. I vote for this. Or maybe if anyone can actually edit the HN source and make the app self-post when it is first of every month (IMO keeping it automated will be easier...)
bigsassy's point about searching is right. It surely makes it easier to browse these threads when you have a dedicated whoishiring user account.
Whoever is posting this, please mention the format of the job posts clearly on every thread (whatever format... this thread <a href="http://news.ycombinator.com/item?id=2057704" >http://news.ycombinator.com/item?id=2057704</a> says location first. It's description is a good example).
Ask HN: Should we agree that this account will submit all Who is Hiring posts?