I've added to my feature TODO list to add "type and capability management" to PowerPress. When added, it will add another menu to PowerPress settings where you can pick specific post types and/or type capabilities.
bheffron: This original thread was "how to manage podcasting by custom post type". You can now do this with PowerPress.
Someone may add a custom post type with a custom type capability, in that case you need to add the following define to your wp-config.php to tell PowerPress to use that capability type in addition to "page" and "post". Here's the define with an example:
What you (bheffron) and cwulff want is to be able to remove podcasting from the default post types of capability type "post" and "page".
To explain again, WordPress added these default capability types. If you add your own custom post type with a capability type of "page" or "post", by default you are provided the podcasting episode boxes by PowerPress, because blog posts and pages can podcast. All other capability types do not get podcasting boxes unless you configure PowerPress otherwise.
It works this way without PowerPress. Just paste a media URL into your own custom post type (with capability type "page" or "post"), click save, then go to your custom fields, you will see WordPress automatically makes that media URL into an "enclosure" (this is a podcast, just without any of the iTunees stuff PowerPress adds).
This is complicated and may take a while before I can add such functionality. Please keep in mind I work on PowerPress in my free time, on occasion I get time from work to develop new features, but for the most part I work on this on nights and weekends. So be patient, no need to be rude!