Yeah, you have to use Wifi to download apps over 20 MB. The podcast restriction only applies to the iTunes app, you can use third-party apps to download larger ones (except in the early days of the App Store, when third party podcast apps were forbidden)
Actually IIRC the whole iTunes music store is also disabled when you're on 3G and not Wifi. (edit: double-checked, yeah it's disabled for me http://db.tt/YT0w0rNQ )
Actually IIRC the whole iTunes music store is also disabled when you're on 3G and not Wifi. (edit: double-checked, yeah it's disabled for me http://db.tt/YT0w0rNQ )