So I finally saw the Luther film. I heartily recommend it. The criticisms I read that accused Fiennes of "underplaying" the character were unwarranted. And various commentators' complaints about "not enough passion" between Luther and Katie I now see to have been mere prurience.
When I first heard about the film a year ago, I had supposed it was Osborne's play (of which I am a great fan). But I'm glad it turned out to be a new telling. Of course, there are things I would have done differently. Passage of time was not well articulated in parts. And I would have added about 15 to 30 minutes of Luther's "conversion" to a biblical understanding of salvation by grace, particularly as he learned it from his study of the Scriptures. But this was not entirely unrepresented in the film.
Every "Reformation Day" I like to dress up like Satan, eat too many candy corns, and do a little public reading from Luther's writings. From now on I may be adding a film-viewing to the party.