First up, I added support for "tag aggregations" - essentially, pages that list all posts with a certain tag. So, any future editions of this audio newsletter that I post can be tagged with "this-week-indieweb-podcast" and will then show up on the "This Week in the IndieWeb Podcast" page. It should soon be possible to feed that page to a tool like Granary to convert the feed on that page, with its audio entries, into an RSS feed suitable for subscribing with a podcast app.
Next up, I added support for "Media Fragments", a W3C recommendation that allows linking to a specific timestamp to start (and even stop!) playback of video and audio. Aaron Parecki's recently implemented this on his own site and was kind enough to share the implementation! Now, you can create links that jump to a specific time of any audio or video post on my site.
For example, if you want to quickly jump to the part of the This Week in the IndieWeb audio edition that contains info about the next upcoming Homebrew Website Club meetings, it looks like this: https://martymcgui.re/2017/02/18/151503/#t=54
Media fragments could enable some fun things, such as a list of links that index directly to particular sections of a long recording.