Teachers interested in preparing students for the Common Core Standards, especially those in English related to writing, should take a gander at the The French Baccalaureat – especially the Philosophy exam that is part of it. The Bac is well-known around the world as a big intellectual challenge for French students, far more important than our college entrance tests in determining one’s future (and much more demanding). Arguably the most famous test is the required exam in Philosophy, involving essay on a few challenging questions (as well as essays in response to lengthy passages from challenging philosophical texts).
Here is a recent blog from an American student studying in France on the Bac.
I thought readers might like to see the questions from the last few years, to get a sense of how another country challenges its students via Essential Questions:

• Is man condemned to create illusions about himself?
• Can we prove a scientific hypothesis?
• Is it our duty to seek out the truth?
• Would we have more freedom without the state?
• Can natural desires exist?
• Is the only purpose of working to be useful?
• What does one gain from working?
• Is every belief contrary to reason?
• Can desire be disinterested?
• Are we prisoners of the past?
• Do artworks have to be pleasurable?
• Do technological developments threaten our liberty?
• Is it absurd to desire the impossible?
• Are there questions that no science answers?
• What does one gain by exchanging?
• Does technical development transform humans?
• Does language betray thought?
• Does historical objectivity presuppose an impartial historian?

Note that the questions are all framed in a way that teachers have long been trained not to do in the US, i.e. frame open-ended questions in a format that suggests that there is a simple yes/no answer to them. I hope you agree with me that these questions actually sharpen thinking and thus show the need for a good argument better than many of the wishy-washy open-ended questions people often give students to write on.
Speaking of questions: Jay McTighe and I have devoted our latest book entirely to Essential Questions. The book is filled with dozens of examples, tips on how to write and edit them, and advice and troubleshooting guidance on how to implement them and – more generally – a culture of inquiry. The book will be out in April 2013, published by ASCD.