Given that most podcasts I get seem to go through https://www.libsyn.com/ or something similar, perhaps we can just talk to large hosters rather than boring holes in HTTPS? :)
I could see, in a few years, non-TLS HTTP serving becoming a premium feature that people will have to pay extra for. In particular, as browsers make various (networking perf) web platform improvements TLS-only, the cost to serve HTTP could easily surpass the cost to serve HTTPS.