Cool, I immediately registered and posted a link (The Ray Wenderlich podcast). Two suggestions though, iTunes, Google, etc. already have decently robust search around podcasts, do you have any plans to reach out to various dev communities (reddit, iOS, Rails, whatever) and getting them to come to you? And then I think the tag system is crucial, for instance tags can't be given a space and custom tags are much less likely to get lots of content then presets.
Awesome project!