Ok, unless I'm missing something, I can't see my podcasts anymore? The only place they appear is in a new "Podcasts" playlist, which isn't much use to me for keeping track of episodes and subscriptions.
Am I just being blind? :-/
You may need to recheck the Podcasts checkbox in the menu
iTunes | Preferences... | General tab. OSX Daily suggests that it may be unchecked by default. Once checked, podcasts should appear under Library rather than as a playlist.
Once you have podcasts showing, using the dropdown upper right, if you switch to list view (weirdly located as one of 3 options in center of entire window, under "progress bar"), if you then click the twirl-down arrow for a podcast, a big gray arrow will automatically show if there are un-dowloaded episodes of that podcast. Click that, and a window will ask you if you want to download all episodes, which obviously you do. It all seems a little odd and seems like Apple needs to work on tis a bit more.