This is one of my favourite podcasts. The show topic can be very dynamic. I've read the last few books they've done for their book club. They usually have a guest or two every show. Sometimes to discuss their books or work.
I usually listen to podcasts on double speed, while running. I can say that the Ruby Rogues podcast, which I have listened to for the last two years, is at least worthy of that.
They "Rogues", as they call themselves, have a variety of backgrounds, from consulting to working on big enterprise companies. All of them came from other languages like Java and .Net, so they appreciate what Ruby brings to the table in terms of codability. It does boast some rockstar Rubyists, namely James Edward Grey.
They have a variety of guests, and cover a range of topics including getting a job, impostor syndrome, mobile development with Ruby Motion, and game development. They also cover a lot of Computer Science-specific topics like functional programming and evented servers.
If you are a Rubyist, or even just a developer who only uses ruby for Chef scripts, I would recommend you check this out. They have a large backlog of great content to choose from.