So, I thought about proposing something similar myself and was interested to see someone like minded.
Anyway, I bring this up because I have given this some thought, and I think "podcasting" might be too narrow of a scope. Or rather, I think a site like this could have its scope expanded to include content creation in general.
My reasoning is that doing any sort of regular content is going into some of the same issues as podcasting. Sure, there are some things that will be specific to podcasting, such as questions about specific platforms. But there are other questions such as, "How often should I post updates?" or, "How can I make my audio have less of an echo?" that will have answers that have use beyond podcasting specifically. Other forms of media, like Youtube will find that useful as well. By expanding to content creation, you can increase the chance of site growth as content creation is a growing field.