I don't have an answer to your question, but the conversation has brought up a few for me.
I'm wondering why folks would want to have a podcast split from their main site too, unless it's for the extra SEO brownie points of having another well ranking site linking back to your main site. While that's a plus, for now, it also makes your audience work harder to follow you. And, if you already have paid hosting, it's easy to get another domain and set up another site there. Would still give you the SEO points.
I believe Feedburner is in a slow, controlled shut down by Google. I would not want to chance a popular show to either free blogging platform, free storage, or free delivery.
Since I also have videos, I host them and the podcast files on AS3.
I publish my podcast on my main site and make the show notes a blog post, along with the audio player, and place it in the podcast category so it can have a feed URL. That's easy to send to iTunes and other services via the PowerPress XML file. (Prior to PowerPress I made my own XML file.)
By having it's own category, I can make it an Interest Group segment in MailChimp and offer it as a subscription that way. Can do the same with Aweber.
Nice thing about MailChimp is that you can import your Feedburner subscribers to your Group and they will not get a double-optin confirmation. It will be seamless. Not so with Aweber, and you may lose a little audience.