If you are using our PowerPress plugin, you don't even need to use category podcasting to separate your podcast from your blog.
Here's an example of a blog with podcasting
www.geeknewscentral.com. About 10% of the blog posts have media, with the podcast only feed added by PowerPress for podcast only readers like iTunes, the site is a good example how blogging and podcasting work well together.
Personally, I think you will get more SEO combining your podcast episodes with your blog posts. Existing blog readers will stumble upon your audio or video and you don't have to worry about duplicate data appearing on two different unique URLs, which actually has negative impact on SEO.