Klinger was seeking declaratory judgement that he could use the non-protected elements. Doyle estate was saying he couldn't. It was agreed by both parties that he couldn't use elements contained in the 10 stories.

From the case listed "And the claim is correct, for he acknowledges that those copyrights are valid and that the only copying he wants to include in his book is copying of the Holmes and Watson characters as they appear in the earlier stories and in the novels."

Mickey Mouse will most certainly not be in the public domain anymore than he is now. Disney can also fall back on trademark law to take care of Disney's use as well.