I'm writing these here instead of in a PM to Craig, so that I can see other's feedback. I may be in the minority and I dont want Craig to follow bad information. I'd like other forum members to comment on my suggestions.
1) Severely limit recapping who you are, or what the PP is. In the latest podcast, Craig went over his whole history again. I was bored. I am impressed by Craig's background, but don't need to hear it again. It almost sounded like Craig may have been intimidated by his interviewee to the point where he felt the need to announce his own credentials. I'm not implying that Craig is arrogant, if anything, insecure. I never hear Larry King announce his credentials before an interview. I don't like the theory of "it's for new fans" because in the podcasting world, a fan will go back and download all the episodes starting from number 1 if they only discover the show later. Then they will be bored when they hear the whole thing again in Ep 1.
2) I loved the guest host with MediumTex. Consider doing more of this. Perhaps with people of different backgrounds, such as a CPA, or a lawyer. Harry had his CPA friend come on one episode and it was brilliant.
3) I like the idea of "live" questions. Have people upload questions to youtube, then play them during the show and answer them. Or setup a Skype time.
4) With podcasts, I find it important to release the show on a set schedule. I dislike the concept of releasing an episode when you have something to talk about. Myself, and most people, are creatures of habit. I'd like to know that Podcast A is released every Monday, so when I come home from work on Tuesday, I know I can listen/watch it. My preference is a weekly episode. Record two at the same time and release them a week apart if there is a holiday and you don't want to record a show that week.
5) Consider a "post of the week" discussion. Pick your favorite most thought provoking thread on the forum that week, and read it on the show, and then discuss it. Have a discussion that is greater than just whatever you may have replied in the topic, otherwise forum readers will be bored. This will also serve as synergy between the podcast and the forum to people who may not know the forum exists. It's one thing to mention the existence of the forum on the podcast, it's another to intrigue people as to the quality of discussion by implementing a weekly segment.
6) Consider a weekly news segment, and discuss it's relation to the PP. For example, Irish bond crisis. What does it mean for PP investors in Ireland? What if an Irish citizen is using Irish treasury bonds for their PP? QE2. What does it mean to PP investors? I imagine that the answer to almost every news segment would be "it doesnt affect the PP, stay the course, the PP was designed exactly for this." That's completely appropriate. I'd like to hear why my portfolio won't be negatively affected by current news.
7) Consider a longer-term regular segment format. For example, every few months, describe the CPI index numbers. Compare them to a real inflation adjusted index of a more realistic basket of goods that you calculate. Perhaps a few sample basket of goods with different weightings. Then compare the PP returns to the real inflation numbers you calculate.

It would take some planning on Craig's part to plan out how to structure the interview so it could be broken down into 2 or 3 logical chunks. This would involve pre-work such as generally planning out the topics of the interview and then keeping the guest on task.
My ideal sample show would be 30 to 45 minutes in duration, each week, exactly released on the same day. Here is an idea for one months worth of episodes.
Episode 1)
a)10 minutes - news of the week segment
b)10 minutes - listener question from youtube
c)10 minutes - listener question from Skype in real time
d)10 minutes - Forum Topic of the Week Discussion, involving the previous Listener who is Skyping Craig
Episode 2)
a) 10 minutes - news of the week segment
b) 20 minutes - part 1 of an interview with Larry Swedroe
c) 10 minutes - Forum Topic of the Week Discussion, possibly involving Larry Swedroe
Episode 3)
a) 10 minutes - news of the week segment
b) 20 minutes - part 2 of an interview with Larry Swedroe (previously recorded)
c) 10 minutes - Forum topic of the week Discussion (cant be with Larry anymore because he wont be "live"
Episode 4)
a) 10 minutes - news of the week segment
b) 10 minutes - Inflation Calculation Discussion for previous 6 months
c) 10 minutes - Listener Skypes in, asks a question, and perhaps discusses inflation topic from previous segment
d) 10 minutes - Forum topic of the week Discussion - perhaps with the previous listener as well on Skype