I stand corrected, iTunes 11.3 is available. 😮 (There's a surprise!)
Given how bad the iTunes 11.2 update was, I will not be updating my iTunes until I understand what the issues are going to be. So currently, I have not yet experienced the Podcast splash screen, so don't know what the problem is. However, I've no doubt someone will post here shortly, to let you know how to get past it.
Sorry I can't be more help at this time. It does sound like the splash screen that appeared in iTunes 11.2 though, so surely they haven't messed this up as well?