I've written about podcasting jobs on a few different occasions (1, 2, 3). To date, nobody has put together a real concerted effort to provide a "podcasting classifieds" type thing. Some podcasting sites have job sections, but they're generally pretty sparse.
The lack of podcasting job sites isn't a reflection on the services, rather it's a reflection of the space right now. There simply are no podcasting jobs outside of the many corporate marketing positions that have expanded their descriptions to include podcasting. No jobs means no market for job sites.
I'm convinced the space will grow as more advertisers and companies become comfortable with the medium as blogging has.
When I first started thinking about this topic a while ago, I went out and bought the podjobshow.com domain. I hadn't put together any really solid idea yet, but it has something to do with being able to start a podcast jobs show at such time when the market actually exists.
As time goes on, I'm seeing more posts like this about podcasters looking for co-hosts. I think the time where the Pod Job Show can launch and continue is approaching faster than I originally thought.