Please note that this list is for the U.S.A.. If you live in another part of the world, these books might still be copyrighted. For example, in the Netherlands (like most of the EU), it is +70 years, meaning we still have to wait 5 more years.
I understand Disney has the rights to the Winnie-the-Pooh character and that they still might cause trouble for those who publish text from the books in Europe.
Works passing into the public domain have very little to do with people actually getting practically slapped around for downloading them. But they have EVERYTHING to do with creating derivative works. If you create a film based on a book that is PD-US but still copyrighted in the EU, you can expect to get sued.
PD terms also affect legal libraries and archive significantly.