Theologian Stanley Hauerwas has an interesting take on Reformation 500 in the Washington Post.  Protestants won.  The RCC has reformed itself to address Luther's critiques. Now what?

That the Reformation has been a success, however, has put Protestantism in a crisis. Winning is dangerous — what do you do next? Do you return to Mother Church? It seems not: Instead, Protestantism has become an end in itself, even though it’s hard to explain from a Protestant point of view why it should exist. The result is denominationalism in which each Protestant church tries to be just different enough from other Protestant churches to attract an increasingly diminishing market share. It’s a dismaying circumstance.

This is an enjoyably provocative essay, but what's missing is an exploration of the ongoing nature of the Reformation, something stressed by most of the traditions.  So though the 16th century issues may have been largely resolved, the Protestant spirit and style opened us up to further developments.  That the RCC may have caught up to the 16th century in the mid-20th doesn't address the 500 years of further development on the part of Protestants.