A few suggestions for the podcast.
My first suggestion would be guests. The shorter length, daily schedule, and perhaps less formal atmosphere seems like it would lend itself to having “friends of the podcast” pop in. Podcasts like Cordkillers, Night Attack (nee NSFW) and The Incomparable use this to great effect. It needn’t be an “expert” to come on and talk about a specific news item within his or her area of expertise; just someone smart and engaging to shoot the breeze with you guys. If I can make a suggestion, please get the Lowdermilk brothers on ASAP.
Second, how about a segment–maybe once a week– where you revisit a recent post (maybe from the last few weeks) that generated a lot of comments/discussion? You could take a few minutes to address the comments or provide additional thoughts/feedback. I know you guys will periodically jump in and reply to a few comments, but there is often a lot of good stuff that develops in there over the course of a week and you obviously can’t reply to all of it individually. But maybe if you’re just picking one article a week to revisit, you could read through all the comments (or at least all the Premium comments), pull out a few facts or questions that readers have shared, then address them.
A third, related suggestion would be a shout-out to particularly good comments. Maybe a “comment of the day”, or the “comments of the week”. It could be something really insightful; or something that provides great details or facts that would have otherwise been overlooked; or maybe a question or explanation that makes you say “hmmm, I wish I thought of that”; or maybe it’s just a really funny comment. It could even be something really terrible or bone-headed; the kind of thing where you’re just like “wait, we need to put a stop to this kind of crap”. Ideally, it would be a mix of all of the above. Hopefully this would inspire commenters to step up their game. It would also be another way to connect you guys and your supporters.
Finally, don’t be afraid to mix it up. Try stuff and see what works. I’ve followed several podcasts from their “alpha” episodes through multi-year anniversaries, and even the best ones took a while to find their footing.