What jockblue1 said - You have to set this individually for each podcast you want by clicking on the title section once you've selected the particular podcast (iphone) or there is a gear button on the top right hand corner for each podcast (ipad).
After about a week of using the app in it's new form.... I decided to delete it last night. While I had most of the functionality I needed such as in-car playing of my podcast playlists and one main list of unplayed podcasts, it was proving to be too unwieldy. Some observations:
Initially, podcasts where I had already played an episode would become unplayed after a couple of days and I would have to go correct this - but the annoyance stopped about 2 days into it. (I had to mark the apple keynote podcast three times as being played cos it kept getting marked as unplayed a day or two later).
I maintain 2 podcast playlists, one for everything unplayed, so the app handled this fine. However, I maintained a second list of certain podcasts I wanted to play without waiting to go through my backlog and this was something that it didn't handle. I would have to navigate through my podcast list to find if I had any unplayed episodes of those particular podcasts. The layout may look good, but in the end I want the simplicity of just being able to select and go without worrying about being hit by a car while crossing the road cos it took too long to look for what i wanted!
I also found that, depending on the particular podcast, sometimes episodes get updated that have a release date that is the same as ones already in the list (eg. podcasts that release several episodes a day). These podcasts would sometimes slot in between the episodes I already have, but haven't actually been downloaded. When I'm watching them at home, progressing through the list and it came across one of these it would download on demand - Great in one respect. However, more often than not, the playback would freeze because it's not streaming fast enough (for video at least). I would have to manually skip these to get to episodes that were pre-downloaded.
I prefer/have gotten used to managing my podcasts on my mac and just having my ios devices play them back without fuss.
Also not helping the clutter is the fact that episodes that have already been played and long forgotten still present themselves in the podcast list (for that specific podcast). The annoyance varies depending on how many past episodes that particular podcast feed decides to retain.
As some others have noticed here already, the podcasts app does seem slower to react than the music app. It would occassionally crash and bomb out (3-4 times in the past week).
I loved the option of being able to play video podcasts at double speed - could speed through some boring/non-visual sections without having to skip them entirely. (I play all my audio ones at double speed, so I have gotten used to it). That was the only benefit I enjoyed out of using the app.
I gave it a go to see if I could live with it and in the end it was just easier to revert back. I manage all my podcasts through the mac anyway, so not being able to download them on the IOS device is not a big loss for me.